Materials Science › Materials Chemistry

Nanoparticles: synthesis and applications

Works Count: 72517

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This cluster of papers focuses on nanotoxicology, particularly the study of the toxic effects of nanoparticles, with a specific emphasis on antimicrobial nanoparticles such as silver. It covers topics such as the biological synthesis of nanoparticles, environmental impact, cytotoxicity, and green synthesis methods.

Keywords

Nanoparticles; Antimicrobial; Toxicity; Silver; Nanomaterials; Biological Synthesis; Environmental Impact; Cytotoxicity; Green Synthesis; Biosynthesis

Silver as Antibacterial Agent: Ion, Nanoparticle, and Metal

2012-12-17

Svitlana Chernousova , Matthias Epple

Abstract The antibacterial action of silver is utilized in numerous consumer products and medical devices. Metallic silver, silver salts, and also silver nanoparticles are used for this purpose. The state … Abstract The antibacterial action of silver is utilized in numerous consumer products and medical devices. Metallic silver, silver salts, and also silver nanoparticles are used for this purpose. The state of research on the effect of silver on bacteria, cells, and higher organisms is summarized. It can be concluded that the therapeutic window for silver is narrower than often assumed. However, the risks for humans and the environment are probably limited.

In vitro toxicity of nanoparticles in BRL 3A rat liver cells

2005-08-26

Saber M. Hussain , K.L. Hess , Jeffery M. Gearhart +2 more

Negligible Particle-Specific Antibacterial Activity of Silver Nanoparticles

2012-07-05

Zongming Xiu , Qingbo Zhang , Hema L. Puppala +2 more

For nearly a decade, researchers have debated the mechanisms by which AgNPs exert toxicity to bacteria and other organisms. The most elusive question has been whether the AgNPs exert direct … For nearly a decade, researchers have debated the mechanisms by which AgNPs exert toxicity to bacteria and other organisms. The most elusive question has been whether the AgNPs exert direct "particle-specific" effects beyond the known antimicrobial activity of released silver ions (Ag+). Here, we infer that Ag+ is the definitive molecular toxicant. We rule out direct particle-specific biological effects by showing the lack of toxicity of AgNPs when synthesized and tested under strictly anaerobic conditions that preclude Ag(0) oxidation and Ag+ release. Furthermore, we demonstrate that the toxicity of various AgNPs (PEG- or PVP- coated, of three different sizes each) accurately follows the dose–response pattern of E. coli exposed to Ag+ (added as AgNO3). Surprisingly, E. coli survival was stimulated by relatively low (sublethal) concentration of all tested AgNPs and AgNO3 (at 3–8 μg/L Ag+, or 12–31% of the minimum lethal concentration (MLC)), suggesting a hormetic response that would be counterproductive to antimicrobial applications. Overall, this work suggests that AgNP morphological properties known to affect antimicrobial activity are indirect effectors that primarily influence Ag+ release. Accordingly, antibacterial activity could be controlled (and environmental impacts could be mitigated) by modulating Ag+ release, possibly through manipulation of oxygen availability, particle size, shape, and/or type of coating.

Review on Zinc Oxide Nanoparticles: Antibacterial Activity and Toxicity Mechanism

2015-04-18

Amna Sirelkhatim , Shahrom Mahmud , Azman Seeni +5 more

Antibacterial activity of zinc oxide nanoparticles (ZnO-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the … Antibacterial activity of zinc oxide nanoparticles (ZnO-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. ZnO-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. ZnO is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered ZnO-NPs antibacterial activity including testing methods, impact of UV illumination, ZnO particle properties (size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species (ROS) including hydrogen peroxide (H2O2), OH− (hydroxyl radicals), and O2 −2 (peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to ZnO-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc ions. These have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on ZnO abrasive surface texture. One functional application of the ZnO antibacterial bioactivity was discussed in food packaging industry where ZnO-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of ZnO-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or inhibition.

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Green synthesis of metal nanoparticles using plants

2011-01-01

Siavash Iravani

In recent years, the development of efficient green chemistry methods for synthesis of metal nanoparticles has become a major focus of researchers. They have investigated in order to find an … In recent years, the development of efficient green chemistry methods for synthesis of metal nanoparticles has become a major focus of researchers. They have investigated in order to find an eco-friendly technique for production of well-characterized nanoparticles. One of the most considered methods is production of metal nanoparticles using organisms. Among these organisms plants seem to be the best candidates and they are suitable for large-scale biosynthesis of nanoparticles. Nanoparticles produced by plants are more stable and the rate of synthesis is faster than in the case of microorganisms. Moreover, the nanoparticles are more various in shape and size in comparison with those produced by other organisms. The advantages of using plant and plant-derived materials for biosynthesis of metal nanoparticles have interested researchers to investigate mechanisms of metal ions uptake and bioreduction by plants, and to understand the possible mechanism of metal nanoparticle formation in plants. In this review, most of the plants used in metal nanoparticle synthesis are shown.

The potential environmental impact of engineered nanomaterials

2003-09-30

Vicki L. Colvin

Silver Colloid Nanoparticles: Synthesis, Characterization, and Their Antibacterial Activity

2006-08-01

Aleš Panáček , Libor Kvı́tek , Robert Prucek +6 more

A one-step simple synthesis of silver colloid nanoparticles with controllable sizes is presented. In this synthesis, reduction of [Ag(NH3)2]+ complex cation by four saccharides was performed. Four saccharides were used: … A one-step simple synthesis of silver colloid nanoparticles with controllable sizes is presented. In this synthesis, reduction of [Ag(NH3)2]+ complex cation by four saccharides was performed. Four saccharides were used: two monosaccharides (glucose and galactose) and two disaccharides (maltose and lactose). The syntheses performed at various ammonia concentrations (0.005−0.20 mol L-1) and pH conditions (11.5−13.0) produced a wide range of particle sizes (25−450 nm) with narrow size distributions, especially at the lowest ammonia concentrations. The average size, size distribution, morphology, and structure of particles were determined by dynamic light scattering (DLS), transmission electron microscopy (TEM), and UV/Visible absorption spectrophotometry. The influence of the saccharide structure (monosacharides versus disaccharides) on the size of silver particles is briefly discussed. The reduction of [Ag(NH3)2]+ by maltose produced silver particles with a narrow size distribution with an average size of 25 nm, which showed high antimicrobial and bactericidal activity against Gram-positive and Gram-negative bacteria, including highly multiresistant strains such as methicillin-resistant Staphylococcus aureus. Antibacterial activity of silver nanoparticles was found to be dependent on the size of silver particles. A very low concentration of silver (as low as 1.69 μg/mL Ag) gave antibacterial performance.

Titanium Dioxide Nanoparticles in Food and Personal Care Products

2012-01-18

Alex Weir , Paul Westerhoff , Lars Fabricius +2 more

Titanium dioxide is a common additive in many food, personal care, and other consumer products used by people, which after use can enter the sewage system and, subsequently, enter the … Titanium dioxide is a common additive in many food, personal care, and other consumer products used by people, which after use can enter the sewage system and, subsequently, enter the environment as treated effluent discharged to surface waters or biosolids applied to agricultural land, incinerated wastes, or landfill solids. This study quantifies the amount of titanium in common food products, derives estimates of human exposure to dietary (nano-) TiO(2), and discusses the impact of the nanoscale fraction of TiO(2) entering the environment. The foods with the highest content of TiO(2) included candies, sweets, and chewing gums. Among personal care products, toothpastes and select sunscreens contained 1% to >10% titanium by weight. While some other crèmes contained titanium, despite being colored white, most shampoos, deodorants, and shaving creams contained the lowest levels of titanium (<0.01 μg/mg). For several high-consumption pharmaceuticals, the titanium content ranged from below the instrument detection limit (0.0001 μg Ti/mg) to a high of 0.014 μg Ti/mg. Electron microscopy and stability testing of food-grade TiO(2) (E171) suggests that approximately 36% of the particles are less than 100 nm in at least one dimension and that it readily disperses in water as fairly stable colloids. However, filtration of water solubilized consumer products and personal care products indicated that less than 5% of the titanium was able to pass through 0.45 or 0.7 μm pores. Two white paints contained 110 μg Ti/mg while three sealants (i.e., prime coat paint) contained less titanium (25 to 40 μg Ti/mg). This research showed that, while many white-colored products contained titanium, it was not a prerequisite. Although several of these product classes contained low amounts of titanium, their widespread use and disposal down the drain and eventually to wastewater treatment plants (WWTPs) deserves attention. A Monte Carlo human exposure analysis to TiO(2) through foods identified children as having the highest exposures because TiO(2) content of sweets is higher than other food products and that a typical exposure for a US adult may be on the order of 1 mg Ti per kilogram body weight per day. Thus, because of the millions of tons of titanium-based white pigment used annually, testing should focus on food-grade TiO(2) (E171) rather than that adopted in many environmental health and safety tests (i.e., P25), which is used in much lower amounts in products less likely to enter the environment (e.g., catalyst supports, photocatalytic coatings).

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Antibacterial properties of nanoparticles

2012-08-09

Mohammad Javad Hajipour , Katharina M. Fromm , Ali Akbar Ashkarran +6 more

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Exposure Modeling of Engineered Nanoparticles in the Environment

2008-05-09

Nicole C. Mueller , Bernd Nowack

The aim of this study was to use a life-cycle perspective to model the quantities of engineered nanoparticles released into the environment. Three types of nanoparticles were studied: nano silver … The aim of this study was to use a life-cycle perspective to model the quantities of engineered nanoparticles released into the environment. Three types of nanoparticles were studied: nano silver (nano-Ag), nano TiO2 (nano-TiO2), and carbon nanotubes (CNT). The quantification was based on a substance flow analysis from products to air, soil, and water in Switzerland. The following parameters were used as model inputs: estimated worldwide production volume, allocation of the production volume to product categories, particle release from products, and flow coefficients within the environmental compartments. The predicted environmental concentrations (PEC) were then compared to the predicted no effect concentrations (PNEC) derived from the literature to estimate a possible risk. The expected concentrations of the three nanoparticles in the different environmental compartments vary widely, caused by the different life cycles of the nanoparticle-containing products. The PEC values for nano-TiO2 in water are 0.7--16 microg/L and close to or higher than the PNEC value for nano-TiO2 (< 1 microg/L). The risk quotients (PEC/PNEC) for CNT and nano-Ag were much smaller than one, therefore comprising no reason to expect adverse effects from those particles. The results of this study make it possible for the first time to carry out a quantitative risk assessment of nanoparticles in the environment and suggest further detailed studies of nano-TiO2.

The role of surface charge in cellular uptake and cytotoxicity of medical nanoparticles

2012-11-01

Eleonore Fröhlich

Abstract: Many types of nanoparticles (NPs) are tested for use in medical products, particularly in imaging and gene and drug delivery. For these applications, cellular uptake is usually a prerequisite … Abstract: Many types of nanoparticles (NPs) are tested for use in medical products, particularly in imaging and gene and drug delivery. For these applications, cellular uptake is usually a prerequisite and is governed in addition to size by surface characteristics such as hydrophobicity and charge. Although positive charge appears to improve the efficacy of imaging, gene transfer, and drug delivery, a higher cytotoxicity of such constructs has been reported. This review summarizes findings on the role of surface charge on cytotoxicity in general, action on specific cellular targets, modes of toxic action, cellular uptake, and intracellular localization of NPs. Effects of serum and intercell type differences are addressed. Cationic NPs cause more pronounced disruption of plasma-membrane integrity, stronger mitochondrial and lysosomal damage, and a higher number of autophagosomes than anionic NPs. In general, nonphagocytic cells ingest cationic NPs to a higher extent, but charge density and hydrophobicity are equally important; phagocytic cells preferentially take up anionic NPs. Cells do not use different uptake routes for cationic and anionic NPs, but high uptake rates are usually linked to greater biological effects. The different uptake preferences of phagocytic and nonphagocytic cells for cationic and anionic NPs may influence the efficacy and selectivity of NPs for drug delivery and imaging. Keywords: endocytosis, plasma membrane, lysosomes, polystyrene particles, quantum dots, dendrimers

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Nanosilver: A nanoproduct in medical application

2007-11-27

X. Chen , Hermann J. Schluesener

Synthesis of metallic nanoparticles using plant extracts

2013-01-12

Amit Kumar Mittal , Yusuf Chisti , Uttam Chand Banerjee

Modeled Environmental Concentrations of Engineered Nanomaterials (TiO2, ZnO, Ag, CNT, Fullerenes) for Different Regions

2009-11-09

Fadri Gottschalk , Tobias Sonderer , Roland W. Scholz +1 more

Engineered nanomaterials (ENM) are already used in many products and consequently released into environmental compartments. In this study, we calculated predicted environmental concentrations (PEC) based on a probabilistic material flow … Engineered nanomaterials (ENM) are already used in many products and consequently released into environmental compartments. In this study, we calculated predicted environmental concentrations (PEC) based on a probabilistic material flow analysis from a life-cycle perspective of ENM-containing products. We modeled nano-TiO2, nano-ZnO, nano-Ag, carbon nanotubes (CNT), and fullerenes for the U.S., Europe and Switzerland. The environmental concentrations were calculated as probabilistic density functions and were compared to data from ecotoxicological studies. The simulated modes (most frequent values) range from 0.003 ng L−1 (fullerenes) to 21 ng L−1 (nano-TiO2) for surface waters and from 4 ng L−1 (fullerenes) to 4 μg L−1 (nano-TiO2) for sewage treatment effluents. For Europe and the U.S., the annual increase of ENMs on sludge-treated soil ranges from 1 ng kg−1 for fullerenes to 89 μg kg−1 for nano-TiO2. The results of this study indicate that risks to aquatic organisms may currently emanate from nano-Ag, nano-TiO2, and nano-ZnO in sewage treatment effluents for all considered regions and for nano-Ag in surface waters. For the other environmental compartments for which ecotoxicological data were available, no risks to organisms are presently expected.

Strain specificity in antimicrobial activity of silver and copper nanoparticles

2007-11-27

Jayesh P. Ruparelia , Arup K. Chatterjee , Siddhartha P. Duttagupta +1 more

A review on plants extract mediated synthesis of silver nanoparticles for antimicrobial applications: A green expertise

2015-03-09

Shakeel Ahmed , Mudasir Ahmad , Babu Lal Swami +1 more

Metallic nanoparticles are being utilized in every phase of science along with engineering including medical fields and are still charming the scientists to explore new dimensions for their respective worth … Metallic nanoparticles are being utilized in every phase of science along with engineering including medical fields and are still charming the scientists to explore new dimensions for their respective worth which is generally attributed to their corresponding small sizes. The up-and-coming researches have proven their antimicrobial significance. Among several noble metal nanoparticles, silver nanoparticles have attained a special focus. Conventionally silver nanoparticles are synthesized by chemical method using chemicals as reducing agents which later on become accountable for various biological risks due to their general toxicity; engendering the serious concern to develop environment friendly processes. Thus, to solve the objective; biological approaches are coming up to fill the void; for instance green syntheses using biological molecules derived from plant sources in the form of extracts exhibiting superiority over chemical and/or biological methods. These plant based biological molecules undergo highly controlled assembly for making them suitable for the metal nanoparticle syntheses. The present review explores the huge plant diversity to be utilized towards rapid and single step protocol preparatory method with green principles over the conventional ones and describes the antimicrobial activities of silver nanoparticles.

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Silver nanoparticles as a new generation of antimicrobials

2008-10-01

Mahendra Rai , Alka Yadav , Aniket Gade

Antimicrobial activity of metals: mechanisms, molecular targets and applications

2013-05-13

Joseph Lemire , Joe J. Harrison , Raymond J. Turner

Biosynthesis of nanoparticles: technological concepts and future applications

2007-08-02

Prashant Mohanpuria , Nisha K. Rana , Sudesh Kumar Yadav

Cytotoxicity and Genotoxicity of Silver Nanoparticles in Human Cells

2008-12-30

P. V. Asharani , Grace Low Kah Mun , M. Prakash Hande +1 more

Silver nanoparticles (Ag-np) are being used increasingly in wound dressings, catheters, and various household products due to their antimicrobial activity. The toxicity of starch-coated silver nanoparticles was studied using normal … Silver nanoparticles (Ag-np) are being used increasingly in wound dressings, catheters, and various household products due to their antimicrobial activity. The toxicity of starch-coated silver nanoparticles was studied using normal human lung fibroblast cells (IMR-90) and human glioblastoma cells (U251). The toxicity was evaluated using changes in cell morphology, cell viability, metabolic activity, and oxidative stress. Ag-np reduced ATP content of the cell caused damage to mitochondria and increased production of reactive oxygen species (ROS) in a dose-dependent manner. DNA damage, as measured by single cell gel electrophoresis (SCGE) and cytokinesis blocked micronucleus assay (CBMN), was also dose-dependent and more prominent in the cancer cells. The nanoparticle treatment caused cell cycle arrest in G2/M phase possibly due to repair of damaged DNA. Annexin-V propidium iodide (PI) staining showed no massive apoptosis or necrosis. The transmission electron microscopic (TEM) analysis indicated the presence of Ag-np inside the mitochondria and nucleus, implicating their direct involvement in the mitochondrial toxicity and DNA damage. A possible mechanism of toxicity is proposed which involves disruption of the mitochondrial respiratory chain by Ag-np leading to production of ROS and interruption of ATP synthesis, which in turn cause DNA damage. It is anticipated that DNA damage is augmented by deposition, followed by interactions of Ag-np to the DNA leading to cell cycle arrest in the G2/M phase. The higher sensitivity of U251 cells and their arrest in G2/M phase could be explored further for evaluating the potential use of Ag-np in cancer therapy.

Nanomaterials in the environment: Behavior, fate, bioavailability, and effects

2008-06-11

Stephen J. Klaine , Pedro J. J. Alvarez , Graeme E. Batley +6 more

The recent advances in nanotechnology and the corresponding increase in the use of nanomaterials in products in every sector of society have resulted in uncertainties regarding environmental impacts. The objectives … The recent advances in nanotechnology and the corresponding increase in the use of nanomaterials in products in every sector of society have resulted in uncertainties regarding environmental impacts. The objectives of this review are to introduce the key aspects pertaining to nanomaterials in the environment and to discuss what is known concerning their fate, behavior, disposition, and toxicity, with a particular focus on those that make up manufactured nanomaterials. This review critiques existing nanomaterial research in freshwater, marine, and soil environments. It illustrates the paucity of existing research and demonstrates the need for additional research. Environmental scientists are encouraged to base this research on existing studies on colloidal behavior and toxicology. The need for standard reference and testing materials as well as methodology for suspension preparation and testing is also discussed.

The Effect of Nanoparticle Size, Shape, and Surface Chemistry on Biological Systems

2012-06-22

Alexandre Albanese , Peter S. Tang , Warren C. W. Chan

An understanding of the interactions between nanoparticles and biological systems is of significant interest. Studies aimed at correlating the properties of nanomaterials such as size, shape, chemical functionality, surface charge, … An understanding of the interactions between nanoparticles and biological systems is of significant interest. Studies aimed at correlating the properties of nanomaterials such as size, shape, chemical functionality, surface charge, and composition with biomolecular signaling, biological kinetics, transportation, and toxicity in both cell culture and animal experiments are under way. These fundamental studies will provide a foundation for engineering the next generation of nanoscale devices. Here, we provide rationales for these studies, review the current progress in studies of the interactions of nanomaterials with biological systems, and provide a perspective on the long-term implications of these findings.

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Occurrence, behavior and effects of nanoparticles in the environment

2007-07-21

Bernd Nowack , Thomas D. Bucheli

Antimicrobial nanomaterials for water disinfection and microbial control: Potential applications and implications

2008-08-28

Qilin Li , Shaily Mahendra , Delina Y. Lyon +4 more

Toxic Potential of Materials at the Nanolevel

2006-02-02

André E. Nel , Tian Xia , Lutz Mädler +1 more

Nanomaterials are engineered structures with at least one dimension of 100 nanometers or less. These materials are increasingly being used for commercial purposes such as fillers, opacifiers, catalysts, semiconductors, cosmetics, … Nanomaterials are engineered structures with at least one dimension of 100 nanometers or less. These materials are increasingly being used for commercial purposes such as fillers, opacifiers, catalysts, semiconductors, cosmetics, microelectronics, and drug carriers. Materials in this size range may approach the length scale at which some specific physical or chemical interactions with their environment can occur. As a result, their properties differ substantially from those bulk materials of the same composition, allowing them to perform exceptional feats of conductivity, reactivity, and optical sensitivity. Possible undesirable results of these capabilities are harmful interactions with biological systems and the environment, with the potential to generate toxicity. The establishment of principles and test procedures to ensure safe manufacture and use of nanomaterials in the marketplace is urgently required and achievable.

Silver nanoparticles: mechanism of antimicrobial action, synthesis, medical applications, and toxicity effects

2012-10-29

S. Prabhu , Eldho K Poulose

Silver nanoparticles are nanoparticles of silver which are in the range of 1 and 100 nm in size. Silver nanoparticles have unique properties which help in molecular diagnostics, in therapies, … Silver nanoparticles are nanoparticles of silver which are in the range of 1 and 100 nm in size. Silver nanoparticles have unique properties which help in molecular diagnostics, in therapies, as well as in devices that are used in several medical procedures. The major methods used for silver nanoparticle synthesis are the physical and chemical methods. The problem with the chemical and physical methods is that the synthesis is expensive and can also have toxic substances absorbed onto them. To overcome this, the biological method provides a feasible alternative. The major biological systems involved in this are bacteria, fungi, and plant extracts. The major applications of silver nanoparticles in the medical field include diagnostic applications and therapeutic applications. In most of the therapeutic applications, it is the antimicrobial property that is being majorly explored, though the anti-inflammatory property has its fair share of applications. Though silver nanoparticles are rampantly used in many medical procedures and devices as well as in various biological fields, they have their drawbacks due to nanotoxicity. This review provides a comprehensive view on the mechanism of action, production, applications in the medical field, and the health and environmental concerns that are allegedly caused due to these nanoparticles. The focus is on effective and efficient synthesis of silver nanoparticles while exploring their various prospective applications besides trying to understand the current scenario in the debates on the toxicity concerns these nanoparticles pose.

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Applications of nanotechnology in food packaging and food safety: Barrier materials, antimicrobials and sensors

2011-07-25

Timothy V. Duncan

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Gold Nanoparticles Are Taken Up by Human Cells but Do Not Cause Acute Cytotoxicity

2005-01-28

Ellen E. Connor , Judith N. Mwamuka , Anand Gole +2 more

A series of gold nanoparticles were examined for uptake and acute toxicity in human leukemia cells. The nanoparticles (average diameter=18 nm), which possessed various surface modifiers, were not toxic to … A series of gold nanoparticles were examined for uptake and acute toxicity in human leukemia cells. The nanoparticles (average diameter=18 nm), which possessed various surface modifiers, were not toxic to cells during continuous exposure for three days. Citrate-capped nanoparticles were further examined for their cellular uptake by absorbance and transmission electron microscopy (see image). Results indicate that although some precursors of nanoparticles may be toxic, the nanoparticles themselves are not necessarily detrimental to cellular function. A series of gold nanoparticles were examined for uptake and acute toxicity in human leukemia cells. The results indicate that although some precursors of nanoparticles may be toxic, the nanoparticles themselves are not necessarily detrimental to cellular function. Nanoscience and nanotechnology hold great promise for many applications, including biomedical uses. Yet despite the huge potential benefit of nanomaterials in the realm of biomedical and industrial applications, very little is known about potential short- and long-term deleterious effects of such nanomaterials on human and environmental health.1–3 Specifically, there is very little information on the effect of size, shape, and surface functional groups on the bioavailability, uptake, subcellular distribution, metabolism, and degradation of many of the nanomaterials being explored. Recent reports have begun to examine these issues for carbon nanotubes,4–6 CdSe nanoparticles,7–10 and gold nanoparticles.11–14 Here we report an investigation of the cellular uptake and cytotoxicity of gold nanoparticles with human cells. The present studies were undertaken in order to determine the interactions of a series of defined nanoparticles containing a variety of surface modifiers and stabilizers with an established human cancer cell line. The nanoparticle library consisted of gold spheres with average diameters of ≈4, 12, or 18 nm, and containing a variety of surface modifiers. Cysteine and citrate-capped 4-nm nanoparticles and glucose-reduced 12-nm nanoparticles were synthesized as previously described (the synthesis of the various nanoparticles employed in this study, along with the materials used, are given in the Supporting Information).15–17 For the 18-nm nanoparticles, the surface modifiers were citrate, biotin, and cetyltrimethylammonium bromide (CTAB).18 The nanoparticle library was tested for cytotoxicity using the K562 leukemia cell line.19 Following three days of continuous exposure to the nanoparticles, cell viability was determined using the MTT assay.20 In this assay, cells that properly metabolize a dye (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) undergo visible color changes that are monitored spectrophotometrically; cells that are incapable of metabolizing the dye remain colorless. The 18-nm nanoparticle preparations with citrate and biotin surface modifiers did not appear to be toxic at concentrations up to 250 μM (gold atoms) under these conditions (Figure 1 A1). In contrast, the gold-salt (AuCl4) precursor solution was over 90 % toxic at a concentration of 200 μM (Figure 1 A1). Note that the gold-salt precursor solution was adjusted to a pH value of 7 prior to the cytotoxicity experiment. The nanoparticle preparations with glucose or cysteine surface modifiers, or with a reduced gold surface, were not toxic at concentrations up to 25 μM. To further confirm the lack of toxicity, cell numbers were counted on days 2–5 during continuous exposure to a 25 μM concentration of 18-nm citrate-capped nanoparticles. No difference was seen in either the growth rate of the untreated control cells or the cells exposed to the nanoparticles (see Supporting Information, Figure S1). Survival curves for human K562 cells exposed to nanoparticles. Cells were continuously exposed to nanoparticles for 3 days. Cell viability was measured by the MTT assay. The data are plotted as the percentage of surviving cells compared to untreated controls. a) Plot showing the survival of cells exposed to the AuCl4 precursor solution (▴) or to 18-nm nanoparticles containing citrate (⧫) or biotin (▪); b) plot showing the survival of cells exposed to CTAB alone (▪), 18-nm nanoparticles with CTAB (⧫), or 18 nm nanoparticles with CTAB that were washed three times prior to incubation with the cells (▴). The preparation of 18-nm nanoparticles that contained CTAB displayed significant toxicity (Figure 1 B1). CTAB alone showed a similar toxicity (Figure 1 B1). It was thus necessary to determine whether unbound CTAB or the CTAB-modified nanoparticles caused the observed cytotoxicity. Therefore, CTAB-modified nanoparticles were centrifuged and washed with deionized water three times to remove unbound CTAB. The washed CTAB-modified nanoparticles were found to be not toxic under the conditions examined, which suggests that CTAB bound to the gold nanoparticles does not cause toxicity (Figure 1 B1). NMR studies of the washed CTAB-modified nanoparticles indicated that all of the remaining CTAB was associated with the nanoparticles (data not shown). The lack of detectable cytotoxicity raised the question of whether the nanoparticles were capable of being taken up into the cells. In order to assess the extent of the uptake of gold nanoparticles into cells, the nanoparticle concentration in the cell culture media was monitored by visible spectroscopy at time points from 1 to 24 h post-exposure (Figure 2 C2). The cells were exposed to 18-nm citrate-capped nanoparticles at a concentration of 25 μM for time points from 15 min to 24 h. The concentration of the gold nanoparticles in the media dropped to a plateau within 1 h of the initial exposure, which suggests that the nanoparticles were rapidly taken up into cells (Figure 2 C2). Control experiments with a media that lacked cells suggested against adsorption of the gold nanoparticles onto serum proteins or the cell culture plates (data not shown). The presence in cells of the 18-nm citrate-capped gold nanoparticles was confirmed by transmission electron microscopy (TEM) of the cells following exposure. Figure 2 A and B2 shows electron micrographs at different magnifications of a cell that contains gold nanoparticles following exposure (to 18-nm citrate-capped nanoparticles) for 1 h. The nanoparticles are clustered in a subcellular location that we speculate are endocytic vesicles, although further experiments would be necessary to conclusively demonstrate this. Interestingly, the images taken at higher magnifications show that the gross morphology of the nanoparticles has not changed dramatically, that is, the nanoparticles appear as ≈18-nm spheres even after being taken up by the cells (Figure 2 B2). Further experiments will be required to determine what, if any, changes to the surface groups on the nanoparticles have occurred after being exposed to the cellular environment. Electron micrographs at different magnifications of a cell containing nanoparticles. Cells were exposed to nanoparticles for 24 h, fixed with osmium tetroxide, sectioned, and visualized with a Hitachi H-8000 electron microscope. a) Image at 8000× magnification of a representative cell with nanoparticles subcellularly localized. The small box represents the area magnified in (b); b) image at 60 000× magnification of gold nanoparticles within cells. The inset is a 150 000× magnification of the gold nanoparticles. c) visible spectroscopy plot (measured at 526 nm) of the concentration of gold nanoparticles in cell culture media following incubation with the cells (data is compared to the initial concentration). The media was exposed to 18-nm citrate-capped nanoparticles for the times shown. Following exposure, the cells were removed from the media by centrifugation at 300 g. Cells were grown in cell culture media lacking phenol red for the absorbance experiments. Taken together, the data suggest that spherical gold nanoparticles with a variety of surface modifiers are not inherently toxic to human cells, despite being taken up into cells. The results with the CTAB-capped nanoparticles and the gold-salt solution indicate that although some precursors of nanoparticles might cause toxicity, the nanoparticles themselves are not necessarily detrimental to cellular function. Many more variables require further testing, including shapes other than spheres, and different functional groups on the surfaces of the nanoparticles. The long-term effects of the presence of nanoparticles would also have to be examined. Lastly, it will be important to determine whether nanoparticles are themselves modified by the cellular environment, thus potentially altering the properties of the nanoparticles for biosensing, imaging, or delivery applications. Supporting information for this article is available on the WWW under http://www.small-journal.com or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Cytotoxicity of Nanoparticles

2007-12-28

Nastassja A. Lewinski , Vicki L. Colvin , Rebekah A. Drezek

Human exposure to nanoparticles is inevitable as nanoparticles become more widely used and, as a result, nanotoxicology research is now gaining attention. However, while the number of nanoparticle types and … Human exposure to nanoparticles is inevitable as nanoparticles become more widely used and, as a result, nanotoxicology research is now gaining attention. However, while the number of nanoparticle types and applications continues to increase, studies to characterize their effects after exposure and to address their potential toxicity are few in comparison. In the medical field in particular, nanoparticles are being utilized in diagnostic and therapeutic tools to better understand, detect, and treat human diseases. Exposure to nanoparticles for medical purposes involves intentional contact or administration; therefore, understanding the properties of nanoparticles and their effect on the body is crucial before clinical use can occur. This Review presents a summary of the in vitro cytotoxicity data currently available on three classes of nanoparticles. With each of these nanoparticles, different data has been published about their cytotoxicity due to varying experimental conditions as well as differing nanoparticle physiochemical properties. For nanoparticles to move into the clinical arena, it is important that nanotoxicology research uncovers and understands how these multiple factors influence the toxicity of nanoparticles so that their undesirable properties can be avoided.

Carbon nanotubes introduced into the abdominal cavity of mice show asbestos-like pathogenicity in a pilot study

2008-05-20

Craig A. Poland , Rodger Duffin , Ian A. Kinloch +7 more

Principles for characterizing the potential human health effects from exposure to nanomaterials: elements of a screening strategy

2005-10-06

Günter Oberdörster , Andrew Maynard , Ken Donaldson +7 more

Abstract The rapid proliferation of many different engineered nanomaterials (defined as materials designed and produced to have structural features with at least one dimension of 100 nanometers or less) presents … Abstract The rapid proliferation of many different engineered nanomaterials (defined as materials designed and produced to have structural features with at least one dimension of 100 nanometers or less) presents a dilemma to regulators regarding hazard identification. The International Life Sciences Institute Research Foundation/Risk Science Institute convened an expert working group to develop a screening strategy for the hazard identification of engineered nanomaterials. The working group report presents the elements of a screening strategy rather than a detailed testing protocol. Based on an evaluation of the limited data currently available, the report presents a broad data gathering strategy applicable to this early stage in the development of a risk assessment process for nanomaterials. Oral, dermal, inhalation, and injection routes of exposure are included recognizing that, depending on use patterns, exposure to nanomaterials may occur by any of these routes. The three key elements of the toxicity screening strategy are: Physicochemical Characteristics, In Vitro Assays (cellular and non-cellular), and In Vivo Assays. There is a strong likelihood that biological activity of nanoparticles will depend on physicochemical parameters not routinely considered in toxicity screening studies. Physicochemical properties that may be important in understanding the toxic effects of test materials include particle size and size distribution, agglomeration state, shape, crystal structure, chemical composition, surface area, surface chemistry, surface charge, and porosity. In vitro techniques allow specific biological and mechanistic pathways to be isolated and tested under controlled conditions, in ways that are not feasible in in vivo tests. Tests are suggested for portal-of-entry toxicity for lungs, skin, and the mucosal membranes, and target organ toxicity for endothelium, blood, spleen, liver, nervous system, heart, and kidney. Non-cellular assessment of nanoparticle durability, protein interactions, complement activation, and pro-oxidant activity is also considered. Tier 1 in vivo assays are proposed for pulmonary, oral, skin and injection exposures, and Tier 2 evaluations for pulmonary exposures are also proposed. Tier 1 evaluations include markers of inflammation, oxidant stress, and cell proliferation in portal-of-entry and selected remote organs and tissues. Tier 2 evaluations for pulmonary exposures could include deposition, translocation, and toxicokinetics and biopersistence studies; effects of multiple exposures; potential effects on the reproductive system, placenta, and fetus; alternative animal models; and mechanistic studies.

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A review of the antibacterial effects of silver nanomaterials and potential implications for human health and the environment

2010-03-22

Catalina Marambio‐Jones , Eric M.V. Hoek

Antimicrobial effects of silver nanoparticles

2007-03-01

Jun Sung Kim , Eunye Kuk , Kyeong Nam Yu +7 more

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Does the Antibacterial Activity of Silver Nanoparticles Depend on the Shape of the Nanoparticle? A Study of the Gram-Negative Bacterium Escherichia coli

2007-01-20

Sukdeb Pal , Yu Kyung Tak , Joon Myong Song

In this work we investigated the antibacterial properties of differently shaped silver nanoparticles against the gram-negative bacterium Escherichia coli, both in liquid systems and on agar plates. Energy-filtering transmission electron … In this work we investigated the antibacterial properties of differently shaped silver nanoparticles against the gram-negative bacterium Escherichia coli, both in liquid systems and on agar plates. Energy-filtering transmission electron microscopy images revealed considerable changes in the cell membranes upon treatment, resulting in cell death. Truncated triangular silver nanoplates with a {111} lattice plane as the basal plane displayed the strongest biocidal action, compared with spherical and rod-shaped nanoparticles and with Ag(+) (in the form of AgNO(3)). It is proposed that nanoscale size and the presence of a {111} plane combine to promote this biocidal property. To our knowledge, this is the first comparative study on the bactericidal properties of silver nanoparticles of different shapes, and our results demonstrate that silver nanoparticles undergo a shape-dependent interaction with the gram-negative organism E. coli.

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The bactericidal effect of silver nanoparticles

2005-08-26

José Rubén Morones‐Ramírez , Jose Luis Elechiguerra , Alejandra Camacho +4 more

Nanotechnology is expected to open new avenues to fight and prevent disease using atomic scale tailoring of materials. Among the most promising nanomaterials with antibacterial properties are metallic nanoparticles, which … Nanotechnology is expected to open new avenues to fight and prevent disease using atomic scale tailoring of materials. Among the most promising nanomaterials with antibacterial properties are metallic nanoparticles, which exhibit increased chemical activity due to their large surface to volume ratios and crystallographic surface structure. The study of bactericidal nanomaterials is particularly timely considering the recent increase of new resistant strains of bacteria to the most potent antibiotics. This has promoted research in the well known activity of silver ions and silver-based compounds, including silver nanoparticles. The present work studies the effect of silver nanoparticles in the range of 1–100 nm on Gram-negative bacteria using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM). Our results indicate that the bactericidal properties of the nanoparticles are size dependent, since the only nanoparticles that present a direct interaction with the bacteria preferentially have a diameter of ∼1–10 nm.

Silver nanoparticles: Green synthesis and their antimicrobial activities

2008-09-18

Virender K. Sharma , Ria A. Yngard , Yekaterina Lin

Pulmonary Toxicity of Single-Wall Carbon Nanotubes in Mice 7 and 90 Days After Intratracheal Instillation

2003-09-29

C. W.-K. Lam

Nanomaterials are part of an industrial revolution to develop lightweight but strong materials for a variety of purposes. Single-wall carbon nanotubes are an important member of this class of materials. … Nanomaterials are part of an industrial revolution to develop lightweight but strong materials for a variety of purposes. Single-wall carbon nanotubes are an important member of this class of materials. They structurally resemble rolled-up graphite sheets, usually with one end capped; individually they are about 1 nm in diameter and several microns long, but they often pack tightly together to form rods or ropes of microscopic sizes. Carbon nanotubes possess unique electrical, mechanical, and thermal properties and have many potential applications in the electronics, computer, and aerospace industries. Unprocessed nanotubes are very light and could become airborne and potentially reach the lungs. Because the toxicity of nanotubes in the lung is not known, their pulmonary toxicity was investigated. The three products studied were made by different methods and contained different types and amounts of residual catalytic metals. Mice were intratracheally instilled with 0, 0.1, or 0.5 mg of carbon nanotubes, a carbon black negative control, or a quartz positive control and euthanized 7 d or 90 d after the single treatment for histopathological study of the lungs. All nanotube products induced dose-dependent epithelioid granulomas and, in some cases, interstitial inflammation in the animals of the 7-d groups. These lesions persisted and were more pronounced in the 90-d groups; the lungs of some animals also revealed peribronchial inflammation and necrosis that had extended into the alveolar septa. The lungs of mice treated with carbon black were normal, whereas those treated with high-dose quartz revealed mild to moderate inflammation. These results show that, for the test conditions described here and on an equal-weight basis, if carbon nanotubes reach the lungs, they are much more toxic than carbon black and can be more toxic than quartz, which is considered a serious occupational health hazard in chronic inhalation exposures.

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Towards a definition of inorganic nanoparticles from an environmental, health and safety perspective

2009-09-13

Mélanie Auffan , Jérôme Rose , Jean‐Yves Bottero +3 more

Biological synthesis of metallic nanoparticles

2009-07-18

Kaushik N. Thakkar , Snehit S. Mhatre , Rasesh Y. Parikh

Comparison of the Abilities of Ambient and Manufactured Nanoparticles To Induce Cellular Toxicity According to an Oxidative Stress Paradigm

2006-07-26

Tian Xia , Michael Kovochich , Jonathan A. Brant +7 more

Nanomaterial properties differ from those bulk materials of the same composition, allowing them to execute novel activities. A possible downside of these capabilities is harmful interactions with biological systems, with … Nanomaterial properties differ from those bulk materials of the same composition, allowing them to execute novel activities. A possible downside of these capabilities is harmful interactions with biological systems, with the potential to generate toxicity. An approach to assess the safety of nanomaterials is urgently required. We compared the cellular effects of ambient ultrafine particles with manufactured titanium dioxide (TiO2), carbon black, fullerol, and polystyrene (PS) nanoparticles (NPs). The study was conducted in a phagocytic cell line (RAW 264.7) that is representative of a lung target for NPs. Physicochemical characterization of the NPs showed a dramatic change in their state of aggregation, dispersibility, and charge during transfer from a buffered aqueous solution to cell culture medium. Particles differed with respect to cellular uptake, subcellular localization, and ability to catalyze the production of reactive oxygen species (ROS) under biotic and abiotic conditions. Spontaneous ROS production was compared by using an ROS quencher (furfuryl alcohol) as well as an NADPH peroxidase bioelectrode platform. Among the particles tested, ambient ultrafine particles (UFPs) and cationic PS nanospheres were capable of inducing cellular ROS production, GSH depletion, and toxic oxidative stress. This toxicity involves mitochondrial injury through increased calcium uptake and structural organellar damage. Although active under abiotic conditions, TiO2 and fullerol did not induce toxic oxidative stress. While increased TNF-α production could be seen to accompany UFP-induced oxidant injury, cationic PS nanospheres induced mitochondrial damage and cell death without inflammation. In summary, we demonstrate that ROS generation and oxidative stress are a valid test paradigm to compare NP toxicity. Although not all materials have electronic configurations or surface properties to allow spontaneous ROS generation, particle interactions with cellular components are capable of generating oxidative stress.

Understanding biophysicochemical interactions at the nano–bio interface

2009-06-14

André E. Nel , Lutz Mädler , Darrell Velegol +6 more

Synthesis of Gold Nanotriangles and Silver Nanoparticles Using Aloe vera Plant Extract

2006-04-07

S. Prathap Chandran , Meena Chaudhary , Renu Pasricha +2 more

Biogenic gold nanotriangles and spherical silver nanoparticles were synthesized by a simple procedure using Aloe veraleaf extract as the reducing agent. This procedure offers control over the size of the … Biogenic gold nanotriangles and spherical silver nanoparticles were synthesized by a simple procedure using Aloe veraleaf extract as the reducing agent. This procedure offers control over the size of the gold nanotriangle and thereby a handle to tune their optical properties, particularly the position of the longitudinal surface plasmon resonance. The kinetics of gold nanotriangle formation was followed by UV-vis-NIR absorption spectroscopy and transmission electron microscopy (TEM). The effect of reducing agent concentration in the reaction mixture on the yield and size of the gold nanotriangles was studied using transmission electron microscopy. Monitoring the formation of gold nanotriangles as a function of time using TEM reveals that multiply twinned particles (MTPs) play an important role in the formation of gold nanotriangles. It is observed that the slow rate of the reaction along with the shape directing effect of the constituents of the extract are responsible for the formation of single crystalline gold nanotriangles. Reduction of silver ions by Aloe veraextract however, led to the formation of spherical silver nanoparticles of 15.2 nm ± 4.2 nm size.

Silver nanoparticles as antimicrobial agent: a case study on E. coli as a model for Gram-negative bacteria

2004-03-20

Ivan Sondi , Branka Salopek‐Sondi

Silver Nanoparticles: Synthesis, Characterization, Properties, Applications, and Therapeutic Approaches

2016-09-13

Xifeng Zhang , Zhi-guo Liu , Wei Shen +1 more

Recent advances in nanoscience and nanotechnology radically changed the way we diagnose, treat, and prevent various diseases in all aspects of human life. Silver nanoparticles (AgNPs) are one of the … Recent advances in nanoscience and nanotechnology radically changed the way we diagnose, treat, and prevent various diseases in all aspects of human life. Silver nanoparticles (AgNPs) are one of the most vital and fascinating nanomaterials among several metallic nanoparticles that are involved in biomedical applications. AgNPs play an important role in nanoscience and nanotechnology, particularly in nanomedicine. Although several noble metals have been used for various purposes, AgNPs have been focused on potential applications in cancer diagnosis and therapy. In this review, we discuss the synthesis of AgNPs using physical, chemical, and biological methods. We also discuss the properties of AgNPs and methods for their characterization. More importantly, we extensively discuss the multifunctional bio-applications of AgNPs; for example, as antibacterial, antifungal, antiviral, anti-inflammatory, anti-angiogenic, and anti-cancer agents, and the mechanism of the anti-cancer activity of AgNPs. In addition, we discuss therapeutic approaches and challenges for cancer therapy using AgNPs. Finally, we conclude by discussing the future perspective of AgNPs.

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The antimicrobial activity of nanoparticles: present situation and prospects for the future

2017-02-01

Linlin Wang , Hu Chen , Longquan Shao

Nanoparticles (NPs) are increasingly used to target bacteria as an alternative to antibiotics. Nanotechnology may be particularly advantageous in treating bacterial infections. Examples include the utilization of NPs in antibacterial … Nanoparticles (NPs) are increasingly used to target bacteria as an alternative to antibiotics. Nanotechnology may be particularly advantageous in treating bacterial infections. Examples include the utilization of NPs in antibacterial coatings for implantable devices and medicinal materials to prevent infection and promote wound healing, in antibiotic delivery systems to treat disease, in bacterial detection systems to generate microbial diagnostics, and in antibacterial vaccines to control bacterial infections. The antibacterial mechanisms of NPs are poorly understood, but the currently accepted mechanisms include oxidative stress induction, metal ion release, and non-oxidative mechanisms. The multiple simultaneous mechanisms of action against microbes would require multiple simultaneous gene mutations in the same bacterial cell for antibacterial resistance to develop; therefore, it is difficult for bacterial cells to become resistant to NPs. In this review, we discuss the antibacterial mechanisms of NPs against bacteria and the factors that are involved. The limitations of current research are also discussed.

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Nanoparticles: Properties, applications and toxicities

2017-05-18

Ibrahim Khan , Khalid Saeed , Idrees Khan

This review is provided a detailed overview of the synthesis, properties and applications of nanoparticles (NPs) exist in different forms. NPs are tiny materials having size ranges from 1 to … This review is provided a detailed overview of the synthesis, properties and applications of nanoparticles (NPs) exist in different forms. NPs are tiny materials having size ranges from 1 to 100 nm. They can be classified into different classes based on their properties, shapes or sizes. The different groups include fullerenes, metal NPs, ceramic NPs, and polymeric NPs. NPs possess unique physical and chemical properties due to their high surface area and nanoscale size. Their optical properties are reported to be dependent on the size, which imparts different colors due to absorption in the visible region. Their reactivity, toughness and other properties are also dependent on their unique size, shape and structure. Due to these characteristics, they are suitable candidates for various commercial and domestic applications, which include catalysis, imaging, medical applications, energy-based research, and environmental applications. Heavy metal NPs of lead, mercury and tin are reported to be so rigid and stable that their degradation is not easily achievable, which can lead to many environmental toxicities.

Cellular uptake of nanoparticles: journey inside the cell

2017-01-01

Shahed Behzadi , Vahid Serpooshan , Wei Tao +7 more

Nanoscale materials are increasingly found in consumer goods, electronics, and pharmaceuticals. While these particles interact with the body in myriad ways, their beneficial and/or deleterious effects ultimately arise from interactions … Nanoscale materials are increasingly found in consumer goods, electronics, and pharmaceuticals. While these particles interact with the body in myriad ways, their beneficial and/or deleterious effects ultimately arise from interactions at the cellular and subcellular level. Nanoparticles (NPs) can modulate cell fate, induce or prevent mutations, initiate cell-cell communication, and modulate cell structure in a manner dictated largely by phenomena at the nano-bio interface. Recent advances in chemical synthesis have yielded new nanoscale materials with precisely defined biochemical features, and emerging analytical techniques have shed light on nuanced and context-dependent nano-bio interactions within cells. In this review, we provide an objective and comprehensive account of our current understanding of the cellular uptake of NPs and the underlying parameters controlling the nano-cellular interactions, along with the available analytical techniques to follow and track these processes.

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Metal nanoparticles: understanding the mechanisms behind antibacterial activity

2017-10-03

Yael N. Slavin , Jason Asnis , Urs O. Häfeli +1 more

As the field of nanomedicine emerges, there is a lag in research surrounding the topic of nanoparticle (NP) toxicity, particularly concerned with mechanisms of action. The continuous emergence of bacterial … As the field of nanomedicine emerges, there is a lag in research surrounding the topic of nanoparticle (NP) toxicity, particularly concerned with mechanisms of action. The continuous emergence of bacterial resistance has challenged the research community to develop novel antibiotic agents. Metal NPs are among the most promising of these because show strong antibacterial activity. This review summarizes and discusses proposed mechanisms of antibacterial action of different metal NPs. These mechanisms of bacterial killing include the production of reactive oxygen species, cation release, biomolecule damages, ATP depletion, and membrane interaction. Finally, a comprehensive analysis of the effects of NPs on the regulation of genes and proteins (transcriptomic and proteomic) profiles is discussed.

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Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

2018-04-03

Jaison Jeevanandam , Ahmed Barhoum , Yen San Chan +2 more

Nanomaterials (NMs) have gained prominence in technological advancements due to their tunable physical, chemical and biological properties with enhanced performance over their bulk counterparts. NMs are categorized depending on their … Nanomaterials (NMs) have gained prominence in technological advancements due to their tunable physical, chemical and biological properties with enhanced performance over their bulk counterparts. NMs are categorized depending on their size, composition, shape, and origin. The ability to predict the unique properties of NMs increases the value of each classification. Due to increased growth of production of NMs and their industrial applications, issues relating to toxicity are inevitable. The aim of this review is to compare synthetic (engineered) and naturally occurring nanoparticles (NPs) and nanostructured materials (NSMs) to identify their nanoscale properties and to define the specific knowledge gaps related to the risk assessment of NPs and NSMs in the environment. The review presents an overview of the history and classifications of NMs and gives an overview of the various sources of NPs and NSMs, from natural to synthetic, and their toxic effects towards mammalian cells and tissue. Additionally, the types of toxic reactions associated with NPs and NSMs and the regulations implemented by different countries to reduce the associated risks are also discussed.

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‘Green’ synthesis of metals and their oxide nanoparticles: applications for environmental remediation

2018-10-30

Jagpreet Singh , Tanushree Dutta , Ki‐Hyun Kim +3 more

In materials science, "green" synthesis has gained extensive attention as a reliable, sustainable, and eco-friendly protocol for synthesizing a wide range of materials/nanomaterials including metal/metal oxides nanomaterials, hybrid materials, and … In materials science, "green" synthesis has gained extensive attention as a reliable, sustainable, and eco-friendly protocol for synthesizing a wide range of materials/nanomaterials including metal/metal oxides nanomaterials, hybrid materials, and bioinspired materials. As such, green synthesis is regarded as an important tool to reduce the destructive effects associated with the traditional methods of synthesis for nanoparticles commonly utilized in laboratory and industry. In this review, we summarized the fundamental processes and mechanisms of "green" synthesis approaches, especially for metal and metal oxide [e.g., gold (Au), silver (Ag), copper oxide (CuO), and zinc oxide (ZnO)] nanoparticles using natural extracts. Importantly, we explored the role of biological components, essential phytochemicals (e.g., flavonoids, alkaloids, terpenoids, amides, and aldehydes) as reducing agents and solvent systems. The stability/toxicity of nanoparticles and the associated surface engineering techniques for achieving biocompatibility are also discussed. Finally, we covered applications of such synthesized products to environmental remediation in terms of antimicrobial activity, catalytic activity, removal of pollutants dyes, and heavy metal ion sensing.

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Therapeutic Potential of Aloe vera and Aloe vera Fabricated Silver Nanoparticles on Reproductive Function in Male Mice Exposed to Hexavalent Chromium

2025-06-26

Tooba Nauroze , Shaukat Ali , Shagufta Andleeb +6 more | Cell Biochemistry and Biophysics

Nanostructured Bentonite-Based Coatings for PVDF Meshes: Antimicrobial Properties and Controlled Drug Release

2025-06-25

A. R. Aliyev , U. A. Hasanova , Aygun Israyilova +2 more | BioNanoScience

Combating antimicrobial resistance: a closer look at disrupting Escherichia coli metabolism and motility with biogenic silver nanoparticles

2025-06-25

Moumita Sil , Shauryabrota Dalui , Abhishek Choudhury +2 more | World Journal of Microbiology and Biotechnology

Metal and metal-oxide nanoparticles inducing changes in reactive oxygen species levels and enzymes of oxidative stress: a review focused on daphnids

2025-06-25

Lucas Gonçalves Queiroz , Susana I. Córdoba de Torresi | Ecotoxicology

Evaluation of Cytotoxicity and Antibacterial Activity of Green Synthesized Silver Nanoparticles using Hedera helix extract.

2025-06-25

Ahmed Hindi Al-Falahi , Sina M. Matalqah , Reem Issa +2 more | Jordan Journal of Pharmaceutical Sciences

Nowadays, silver nanoparticles (AgNPs) have drawn significant interest due to their unique properties, making them advantageous in biomedical applications, sensors, antimicrobial agents, catalysts, and optical fibers. Green synthesis is the … Nowadays, silver nanoparticles (AgNPs) have drawn significant interest due to their unique properties, making them advantageous in biomedical applications, sensors, antimicrobial agents, catalysts, and optical fibers. Green synthesis is the safest and easiest method for producing silver nanoparticles (AgNPs). This study aimed to investigate the antibacterial and cytotoxic activities of silver nanoparticles synthesized using aqueous extracts of Hedera helix (AHE) against S. aureus, P. aeruginosa, and A549 lung cancer cell lines. Silver nanoparticles (Hh-AgNPs) were synthesized using the aqueous extracts of Hedera helix (AHE) as a reducing agent and polyvinylpyrrolidone (PVP) as a stabilizer and characterized by UV-visible spectrophotometry and particle size analysis via dynamic light scattering (DLS). The silver nanoparticles (Hh-AgNPs) were successfully synthesized, showing maximum absorption at 448 nm, with enhanced cytotoxic activity against A549 lung cancer cell lines (IC₅₀ = 15.16 µg/ml) and antibacterial activity against S. aureus (MIC = 0.156 mg/ml) and P. aeruginosa (MIC = 0.3125 mg/ml), compared to AHE alone. Biological methods are cost-effective and eco-friendly and thus can serve as an economical and efficient alternative for the large-scale synthesis of silver nanoparticles.

Preface

2025-06-25

| Royal Society of Chemistry eBooks

Antimicrobial effects produced by gold nanoparticles obtained with extracts of Allium sativum and Allium ursinum

2025-06-25

Ioana Barbu , Rahela Carpa , Oana Maria Biro +1 more | Studia Universitatis Babeş-Bolyai Biologia

Gold nanoparticles (AuNPs) obtained by green synthesis using plant extracts from the genus Allium have attracted significant scientific interest due to their potential applications as antimicrobial agents in the biomedical … Gold nanoparticles (AuNPs) obtained by green synthesis using plant extracts from the genus Allium have attracted significant scientific interest due to their potential applications as antimicrobial agents in the biomedical field. This study investigates the antimicrobial potential of AuNPs obtained by green synthesis using extracts of Allium sativum and Allium ursinum. These plant extracts are rich in sulfur compounds (allicin), flavonoids and polyphenols, which not only facilitate the formation of nanoparticles, but also confer them increased antimicrobial properties. The nanoparticles thus obtained were characterized by spectroscopic methods (UV-Vis) and were tested for antimicrobial activity. Microbiological tests performed in vitro demonstrated an antimicrobial activity of the nanoparticles against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria but also against Candida albicans and Candida parapsilosis. The results support the idea that gold nanoparticles functionalized with Allium extracts may constitute a promising alternative in the development of natural antimicrobial compounds with applications in medicine, the food industry and the pharmaceutical field. Article history: Received 16 May 2025; Revised 29 May 2025;Accepted 29 May 2025; Available online 25 June 2025

Utilization of affordable nanocomposites with outstanding antimicrobial activity in waterborne coatings

2025-06-25

Walaa M. Abd El-Gawad | Scientific Reports

Abstract This study aimed to explore the development of eco-friendly antimicrobial coatings by combining antimicrobial nanocomposites with waterborne resins. Novel nanocomposites, such as nano-ZnO/silica fume and nano-CuO/silica fume, were synthesized … Abstract This study aimed to explore the development of eco-friendly antimicrobial coatings by combining antimicrobial nanocomposites with waterborne resins. Novel nanocomposites, such as nano-ZnO/silica fume and nano-CuO/silica fume, were synthesized using the solution combustion method, along with pure nano-ZnO and nano-CuO. The nanocomposites consist of a thin layer of nanometal oxide on silica fume, aiming to enhance antimicrobial activity. These nanocomposites were incorporated into acrylic waterborne resin at two concentrations (0.4 and 0.8 wt%) to provide cost-effective alternatives to imported and expensive antimicrobial agents. Antimicrobial effectiveness was evaluated against Staphylococcus aureus , Micrococcus luteus , and Candida albicans using disc diffusion and shake flask methods. Besides, the mechanical and physical properties of the coatings were compared to the properties of a commercial coating. The findings showed that the commercial coating offered inhibition zones ranging from 16 to 21 mm. While the disc containing 0.8% nano-ZnO/silica fume offered the greatest antimicrobial activity, with inhibitory zones ranging from 17 to 26.6 mm. Additionally, the results demonstrated that discs containing nano-ZnO were better than discs containing nano-CuO. The mechanical properties indicated that the hardness of coatings with either nano-ZnO or nano-CuO is similar to the commercial coatings in group I. However, coatings with nano-ZnO/silica fume and nano-CuO/silica fume exhibited slightly higher hardness. In group II, higher ratios of nano-ZnO, nano-CuO, and their silica fume composites significantly increase hardness compared to the commercial coatings, attributed to the formation of a more compact film. Moreover, the results showed that coatings with a high ratio of pigments (0.8%) adhered better than those with 0.4% of pigments.

One-Step Synthesis of Monometallic and Bimetallic Nickel Nanoparticles Using Murraya koenigii L. and Investigation of Various Bioactivities

2025-06-24

Tauheeda Riaz , Mumtaz Ali , Sana Mansoor +7 more | Topics in Catalysis

Toxicity and transport of nanoparticles in agriculture: effects of size, coating, and aging

2025-06-24

Shahid Ul Islam | Frontiers in Nanotechnology

The increasing application of engineered nanoparticles (ENPs) in agriculture for enhanced crop production and protection has raised significant concerns about their environmental fate and potential toxicity. This review examines how … The increasing application of engineered nanoparticles (ENPs) in agriculture for enhanced crop production and protection has raised significant concerns about their environmental fate and potential toxicity. This review examines how particle size, surface coating, and aging influence the transport and toxicity of nanoparticles in agricultural ecosystems. Smaller nanoparticles exhibit greater mobility and reactivity, often leading to increased plant uptake and potential phytotoxic effects, including reduced germination, root inhibition, and oxidative stress. Surface coatings, such as polyethylene glycol (PEG) or natural organic matter, play a crucial role in modulating nanoparticle behavior by stabilizing dispersion, altering bioavailability, and mitigating toxicity. As nanoparticles age in the environment, processes like sulfidation, oxidation, and biotransformation modify their physicochemical properties, often reducing their toxicity but complicating their long-term environmental behavior. The interaction of these variables with soil properties, microbial communities, and plant systems underscores the complexity of nanoparticle dynamics in agricultural settings. While laboratory studies have provided valuable insights, long-term field data and assessments under realistic agrarian conditions remain limited. A better understanding of these factors is essential for predicting environmental impacts and guiding the development of safer and more sustainable nanotechnologies in agriculture. The increasing use of nanoparticles (NPs) in various industrial and consumer applications has led to their inevitable release into agricultural ecosystems. This review article explores the environmental fate, transport, and toxicity of NPs in agroecosystems, emphasizing how particle size, surface coating, and aging influence their interactions with soil, water, plants, and microorganisms. Mechanistic insights, recent findings, and knowledge gaps are discussed to inform safer nanoparticle design and sustainable agricultural practices.

Photocatalytic Degradation of Coomassie Brilliant Blue R-250 and Antimicrobial Activities of Iron Oxide Nanoparticles Synthesized by Aspergillus flavus

2025-06-24

Rania R Elkhouli , Khaled El-Baghdady , Mostafa M.H. Khalil +1 more | Current Microbiology

Identification and mitigation of blood’s interference with the antimicrobial activity of AgNbO3 particles

2025-06-24

Cyrus Talebpour , Fereshteh Fani , Marc Ouellette +3 more | PLoS ONE

The detrimental impact of blood on the antimicrobial activity of AgNbO 3 particles was identified and investigated. It was observed that the impact is more severe in the case of … The detrimental impact of blood on the antimicrobial activity of AgNbO 3 particles was identified and investigated. It was observed that the impact is more severe in the case of lysed blood. The same phenomenon also operates in the case of commonly used silver salt, AgNO 3 . The inhibition was shown to be due to hemoglobin, but may be unrelated to the heme moiety. In an attempt to find additives to mitigate the inhibitory effect of hemoglobin, iron ions and the chelating agent, K 2 EDTA, were initially considered as potential candidates. Including ferric iron on the particles was shown to have a marginal effect, but supplying the medium with K 2 EDTA chelating agent, provided a better outcome for countering the deleterious impact of hemoglobin on AgNbO 3 activity. These findings may be relevant for adapting the silver compounds to applications such as wound dressings, where silver’s antimicrobial action would have to take place in a blood containing environment.

Elucidating the Role of Engineered Cerium Oxide Nanoparticles on Soil-Water Capacity Properties: A Pedostructure Perspective

2025-06-24

Zainab Ashkanani , Rabi H. Mohtar , Xingmao Ma +3 more | ACS Applied Engineering Materials

Ag nanoparticles in metal oxide highly supportive for photocatalytic and cytotoxic properties: experimental and theoretical analysis

2025-06-24

Vanessa Ávila-Segura , Eduardo Daniel Tecuapa-Flores , Carlos Alberto Huerta‐Aguilar +2 more | International Journal of Environmental & Analytical Chemistry

Green synthesized ZnO nanoparticles using Jatropha curcas latex for antibacterial applications

2025-06-24

Yojana Sharma , Vikas Anand , Rajesh Kumar +2 more | Next Materials

Green synthesis of ZnO nanoparticles: Characterization and emerging applications in sustainable agriculture

2025-06-24

Nitu Rani , Narashans Alok Sagar , Arjun Chauhan +1 more | Industrial Crops and Products

Nano-driven cultivation of medicinal plants: Exploring biological efficacy and phytotoxicological impacts

2025-06-24

Naveen P. Singh , S. K. Bhalla , Vivek Sharma +2 more | South African Journal of Botany

Antimicrobial and Anti-Inflammatory Potentials of Silver Tungstate Nanoparticles, Cytotoxicity and Interference on the Activity of Antimicrobial Drugs

2025-06-23

Washington de Souza Leal , Juliane Z. Marinho , Isabela P. Cerávolo +3 more | Drugs and Drug Candidates

Background: Bacterial resistance to antimicrobial drugs is a critical phenomenon that is hampering clinical treatments, raising the need for promising compounds that can be explored as pharmaceutical products. This study … Background: Bacterial resistance to antimicrobial drugs is a critical phenomenon that is hampering clinical treatments, raising the need for promising compounds that can be explored as pharmaceutical products. This study investigated the antimicrobial potential of α-Ag2WO4–alpha phase, orthorhombic structure silver tungstate nanoparticles (STN), against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, alone and combined to clinically relevant antimicrobial drugs. Methods: We used classical methods (MIC/checkerboard) to investigate the antimicrobial activity of STN. We characterized STN using X-ray diffraction, photoluminescence and scanning electron microscopy. We also performed cytotoxicity tests on BGM cells and anti-inflammatory tests in vitro. Results: STN was effective at 128 µg/mL for S. aureus and at 256 µg/mL for E. coli, but was not effective against P. aeruginosa. When combined with antimicrobials, STN decreased their MIC values, and its anti-inflammatory potential was confirmed. CC50 of STN was of 16.23 ± 1.09 μg/mL against BGM cells. Conclusions: Our data open doors for further studies in animal models to investigate the effects on STN in infectious diseases.

Green and Chemical Synthesis of Copper Oxide Nanoparticles for Antifungal Protection and Plant Growth Enhancement of Chickpea via Nanopriming

2025-06-23

Krinal S. Bambharoliya , Bhavin Bhatt , Prafull Salvi +3 more | Journal of Agricultural and Food Chemistry

This study reports the synthesis of copper oxide nanoparticles (CuO NPs) using chemical and green methods utilizing pineapple waste, including fresh peels, dried peels, and pineapple pomace from two different … This study reports the synthesis of copper oxide nanoparticles (CuO NPs) using chemical and green methods utilizing pineapple waste, including fresh peels, dried peels, and pineapple pomace from two different copper precursors, targeting antifungal activity and plant growth enhancement. Phytochemical analysis confirmed the presence of bioactive compounds with dry peel extract proving to be most effective for green synthesis. CuO NP formation was evidenced by color change and confirmed by UV-vis, Fourier transform infrared (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM) analysis, revealing particle sizes under 50 nm. Green CuO NPs (GN) exhibited a better stability and superior antifungal activity against Fusarium oxysporum f. sp. ciceri (64.20% inhibition at 1000 ppm), was lower than those of chemically synthesized NPs and precursors. In chickpea seed priming, GN significantly enhanced germination (100%), root length (11.3 cm), and seedling length (13.9 cm) at 250 ppm, indicating improved root-to-shoot balance and biomass accumulation. Thus, pineapple waste-derived CuO NPs offer a sustainable, eco-friendly solution for both disease management and growth promotion in chickpea.

Microalgae mediated nanoparticles synthesis over conventional approaches: agricultural sustainability perspective

2025-06-23

H. S. Shinde , A.V Waghmode , Pavitra Chippalakatti +2 more | Nanotechnology for Environmental Engineering

Synthesis of Eco-friendly Silver Nanoparticles (AgNPs) by Lacticaseibacillus rhamnosus for Combating Antibiotic Resistance and Boosting Antioxidant Activity

2025-06-23

Ragala Venkata Nandha , Maheswari Paulraj , A. R. Heamchandsaravanan +3 more | International Journal of Pathogen Research

Antimicrobial resistance (AMR) is an imperative global health threat, prompting the need to design novel therapeutic options. In this work, silver nanoparticles (AgNPs) were biosynthesised from Lacticaseibacillus rhamnosus using a … Antimicrobial resistance (AMR) is an imperative global health threat, prompting the need to design novel therapeutic options. In this work, silver nanoparticles (AgNPs) were biosynthesised from Lacticaseibacillus rhamnosus using a green synthesis method. Characterisation was ensured by a colour change visible to the naked eye and a UV–Visible absorption maximum at 429 nm. The antimicrobial activity of the biosynthesised AgNPs (AgNPs-LR) was tested against standard and multidrug-resistant (MDR) strains of bacteria through agar well diffusion and MIC assays. The findings showed potent, dose-dependent antibacterial potential, with clear zones of inhibition recorded in Escherichia coli (ESBL, 19 mm) and Klebsiella pneumoniae (MDR, 17 mm) at 150 µL. MIC analysis showed high sensitivity in E. coli and Pseudomonas aeruginosa ATCC strains (MIC <2 µg/mL), whereas Serratia marcescens and K. pneumoniae (MDR) were inhibited at ≤8 µg/mL, validating the broad-spectrum potential of AgNPs-LR, especially against Gram-negative and MDR pathogens. Gram-positive strains manifested variable resistance, suggesting the necessity for further optimisation of formulation. Moreover, AgNPs-LR manifested concentration-dependent antioxidant activity in the DPPH radical scavenging assay, exhibiting comparable performance to ascorbic acid at elevated concentrations. The above findings reinforce the dual functionality of AgNPs-LR as a potent antimicrobial and antioxidant compound, and thus underscore its potential as a viable candidate for the fight against AMR and oxidative stress management in biomedical applications.

Toxicological assessment and risk management of nanoparticles mediated composite materials-critical review: state of the art

2025-06-23

Gaurav Pathak , Swati Mangla , Guddu Kumar Gupta +2 more | Discover Polymers.

Green Synthesis of Silver Nanoparticles Using Pongamia pinnata Methanolic Extract and Their Antifertility Impact on Male Rats: A TEM Study

2025-06-23

Prity Yadav , Neha Bharti , Pratap Chand Mali | Research Square (Research Square)

<title>Abstract</title> The present study explores the green synthesis of silver nanoparticles (AgNPs) using methanolic leaf extract of <italic>Pongamia pinnata</italic> and investigates their potential antifertility effects in male Wistar rats. The … <title>Abstract</title> The present study explores the green synthesis of silver nanoparticles (AgNPs) using methanolic leaf extract of <italic>Pongamia pinnata</italic> and investigates their potential antifertility effects in male Wistar rats. The synthesized AgNPs were characterized by UV–Visible spectroscopy, FTIR, XRD, and SEM, confirming their nanoscale size, crystalline nature, and the presence of biofunctional groups responsible for stabilization and reduction. Male rats were orally administered AgNPs for 60 days, and testicular tissue was subsequently examined for ultrastructural changes using transmission electron microscopy (TEM) and histological analysis of epididymis y using light microscope. TEM analysis revealed significant alterations in the seminiferous tubules, including disorganized germinal epithelium, vacuolization, and mitochondrial damage, indicating impaired spermatogenesis. Additionally, biochemical analysis of the reproductive tissues showed a marked decrease in total protein content compared to control groups, suggesting disruption of normal cellular metabolism and structural protein synthesis. These findings highlight the possible antifertility effects of biosynthesized AgNPs, mediated through oxidative stress and protein degradation pathways. This study underscores the dual role of <italic>Pongamia pinnata</italic>-mediated AgNPs in nanomedicine and reproductive toxicology, providing insights into their biological impact and potential use in male contraception research.

Unravelling the use of nanotechnology for crop pest management as a green and sustainable agriculture

2025-06-22

B. Kariyanna , M Sowjanya | The Journal of Basic and Applied Zoology

Abstract Background Humans are looking for innovative options to combat major problematic biotic hurdles like crop pests (insect pests and diseases) in agriculture. Synthetic pesticides are widely employed to control … Abstract Background Humans are looking for innovative options to combat major problematic biotic hurdles like crop pests (insect pests and diseases) in agriculture. Synthetic pesticides are widely employed to control pests and diseases, which leads to several issues, including pest resistance, eradication of natural enemies, contamination of the environment, biodiversity loss and health risks to humans. This review will shed light on future alternatives for crop pest management. Mani body Nanotechnology is one of the most innovative and promising alternatives for crop pest management to handle problems associated with chemical pesticides by converting the active element to nanoparticles (NPs). Because of the bigger surface area, NPs guarantee that a greater volume comes into touch with the surfaces. According to numerous research findings, nanopesticide formulations derived from NPs successfully manage crop pests and other biotic stress. They offer a long-term controlled release of the pesticide molecules, which are more environmentally friendly, selective, and target specific. Additionally, the quantity of nanopesticides needed to control insects is smaller, which lowers the chemical burden on the environment. Conclusion As an alternative to chemical molecules, nanopesticides act as a very important tool for managing insect pests and diseases. Technologies such as smart pest monitoring, precision delivery, nano-RNAi and target release nanopesticides create new avenues for pest surveillance and management. Therefore, adopting nanotechnology to develop nanopesticides and nanotools for crop pest management is thought to be the finest method in green farming for sustainable agriculture and the environment. So this article focuses more on the innovation in nanotechnology for crop pest management. Graphical abstract

Aesculus hippocastanum extract-mediated biosynthesis of silver-decorated zinc oxide nanoparticles and investigation of their photocatalytic, antibacterial, and antioxidant properties

2025-06-22

Sobhan Mortazavi‐Derazkola , Maryam Samadipour , Pouria Mohammadparast‐Tabas +1 more | Bioprocess and Biosystems Engineering

Synthesis and Antibacterial Evaluation of Silver-Coated Magnetic Iron Oxide/Activated Carbon Nanoparticles Derived from Hibiscus esculentus

2025-06-21

Müslüm Güneş , Erdal Ertaş , Şeyhmus Tümür +7 more | Magnetochemistry

The increasing prevalence of antimicrobial resistance alongside the pharmacological limitations and adverse effects associated with conventional antibiotics necessitates the development of novel and efficacious antimicrobial agents. In this study, magnetic … The increasing prevalence of antimicrobial resistance alongside the pharmacological limitations and adverse effects associated with conventional antibiotics necessitates the development of novel and efficacious antimicrobial agents. In this study, magnetic iron oxide nanoparticles (MIONPs) were synthesized via a chemical co-precipitation method. Activated carbon (AC) derived from Hibiscus esculentus (HE) fruit was coated onto the nanoparticle surfaces to fabricate MIONPs/HEAC nanocomposites. To augment their antimicrobial properties, silver ions were chemically reduced and deposited onto the MIONPs/HEAC surface, yielding MIONPs/HEAC@Ag nanocomposites. Comprehensive characterization of the synthesized nanocomposites was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), dynamic light scattering (DLS), and zeta potential analysis. DLS measurements indicated average particle sizes of approximately 122 nm and 164 nm for MIONPs/HEAC and MIONPs/HEAC@Ag, respectively. Saturation magnetization values were determined to be 73.6 emu/g for MIONPs and 65.5 emu/g for MIONPs/HEAC. Antibacterial assays demonstrated that MIONPs/HEAC@Ag exhibited significant inhibitory effects against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, with inhibition zone diameters of 11.50 mm and 13.00 mm, respectively. In contrast, uncoated MIONPs/HEAC showed negligible antibacterial activity against both bacterial strains. These findings indicate that MIONPs/HEAC@Ag nanocomposites possess considerable potential as antimicrobial agents for biomedical applications, particularly in addressing infections caused by antibiotic-resistant bacteria.

Comparison of genotoxic and cytotoxic effects of single-walled and multi-walled carbon nanotubes on Chlorella vulgaris

2025-06-21

Mozhgan Emtyazjoo , Atena Sheibani nia , Salomeh Payvar +1 more | Toxicological & Environmental Chemistry Reviews

Eco-friendly synthesis of cobalt nanoparticles from Erythrina crista-galli leaves for enhanced anticorrosive performance

2025-06-20

Dilpreet Kaur , Monika Verma , Ruchi Bharti +2 more | Chemical Papers

Pharmacokinetic and Toxicological Aspects of Carbon Nanotubes

2025-06-20

Sonali Batra , Sumit Sharma , Navjot Kanwar +4 more | CRC Press eBooks

Production of copper nanoparticles using genetically engineered Komagataella phaffii

2025-06-20

Cheng‐Di Dong , Fan Wu , Shufan Liu +5 more | Bioprocess and Biosystems Engineering

Exploring the anticancer potential of green silver Nanoparticles–Paclitaxel nanocarrier on MCF-7 breast Cancer cells: an in vitro approach

2025-06-20

M. B. Aboul-Nasr , Alaa A. Yasien , Sabah S. Mohamed +2 more | Scientific Reports

Abstract Paclitaxel (PTX) is a potent chemotherapeutic agent limited by poor solubility and adverse effects. To address these challenges, we developed a novel nanocomposite combining PTX purified from the endophytic … Abstract Paclitaxel (PTX) is a potent chemotherapeutic agent limited by poor solubility and adverse effects. To address these challenges, we developed a novel nanocomposite combining PTX purified from the endophytic fungus A. fumigatiaffinis PP235788.1 with biosynthesized silver nanoparticles (AgNPs) from the same fungal strain. The PTX-AgNP conjugate (28.48 ± 0.13 nm) was characterized by UV-Vis, XRD, and TEM, revealing monodisperse AgNPs (14.50 ± 0.58 nm) as the core component. In vitro studies demonstrated significant cytotoxicity against MCF-7 breast cancer cells (IC₅₀= 1.7 µg/mL, p < 0.001), with 5-10-fold greater efficacy than AgNPs alone. Annexin V/PI staining and DNA fragmentation assays confirmed apoptosis induction, highlighting the conjugate’s enhanced anticancer activity. This eco-friendly nano platform synergizes PTX’s therapeutic effects with AgNP-mediated targeting, offering a promising strategy to reduce side effects while improving tumor-specific cytotoxicity for advanced cancer therapy.

A Comprehensive Review on Green Synthesis of ZnO Nano Particles and its Applications in Photocatalysis

2025-06-20

Santosh Kumar Nathsharma | International Journal of Innovations in Science Engineering and Management.

One of the biggest issues facing humanity globally is water pollution. The discharge of untreated wastewater from urbanisation and population growth poses a serious danger to natural water supplies. Metal … One of the biggest issues facing humanity globally is water pollution. The discharge of untreated wastewater from urbanisation and population growth poses a serious danger to natural water supplies. Metal oxide is one of the most often used photosensitive catalysts in the photocatalysis process, which breaks down pollutants. Instead of using metal oxide in its bulk form, nanosized metal oxide is being employed to boost the photocatalytic activity. This review highlights the significant potential of green-synthesized ZnO nanoparticles (ZnO NPs) in photocatalytic applications. Various plant-based methods, including the use of brinjal calyxes and rosin from Pinus latteri, have demonstrated eco-friendly, low-cost, and efficient routes for ZnO NP synthesis. Overall, green synthesis offers a sustainable alternative to conventional chemical methods, producing highly active and environmentally benign nano catalysts. This makes green-synthesized ZnO NPs as promising candidates for wastewater treatment and broader environmental remediation efforts.

Effects of Zinc Oxide Nanoparticles on Growth and Secondary Metabolite Accumulation in In Vitro Culture of Ocimum basilicum L.

2025-06-20

Funda Yılmaz Baydu , Ersan Bektaş | Journal of Apitherapy and Nature

The study investigated the effects of zinc oxide nanoparticle (ZnO-NP) on the growth, secondary metabolite accumulation, and antioxidant activity of Ocimum basilicum L. (basil) shoots in vitro. Various concentrations of … The study investigated the effects of zinc oxide nanoparticle (ZnO-NP) on the growth, secondary metabolite accumulation, and antioxidant activity of Ocimum basilicum L. (basil) shoots in vitro. Various concentrations of ZnO-NP (5, 10, 20, 40 and 50 mg/L) were applied to assess their impact on growth parameters such as shoot elongation, node and leaf numbers, shoot multiplication rate, root formation percentage, and root length. Results showed that lower ZnO-NP concentrations stimulated shoot elongation, while higher concentrations negatively affected root development. Total phenolic content (TPC) and antioxidant activity were assessed in methanolic extracts, with higher TPC observed in roots compared to stems. The antioxidant capacity, evaluated using DPPH and CUPRAC assays, showed variable responses to ZnO-NP concentrations, with higher antioxidant activity (SC50: 0.77 mg/mL and 0.512 mmol TE/g plant, respectively) detected at 40 mg/L ZnO-NP concentration in roots. Additionally, the study analyzed rosmarinic acid content, the main phenolic compound in O. basilicum, and found that its accumulation increased with ZnO-NP application, especially in roots at the 40 mg/L ZnO-NP concentration with the value of 35.98 µg phenolic/mg plant. Overall, the findings suggest that ZnO-NP application influences growth, secondary metabolite accumulation, and antioxidant activity in O. basilicum, with effects varying based on concentration and plant part.

Emerging trends and perspectives on nano-fertilizers for sustainable agriculture

2025-06-20

Ankush Goyal , Sachin Chavan , Rajendra A Mohite +3 more | Discover Nano

The intensifying global demand for agricultural products has been met with the excessive use of conventional fertilizers, leading to significant environmental pollution, soil and water degradation, and public health concerns. … The intensifying global demand for agricultural products has been met with the excessive use of conventional fertilizers, leading to significant environmental pollution, soil and water degradation, and public health concerns. This challenge has been further exacerbated by the pressures of globalization, necessitating the adoption of more sustainable and efficient farming practices. As a promising solution to these issues, nanotechnology has been explored for its innovative approaches to enhance nutrient delivery and reduce environmental impact. In this review, the potential of various nano-fertilizers-including nano-NPK, nano-nitrogen (N), nano-phosphorous (P), nano-potassium (K), nano-iron (Fe), hydroxyapatite (HAP)-modified urea nanoparticles, and nano-zeolite composite fertilizers-has been investigated for improving crop productivity and sustainability. The applications in key crops such as wheat, potato, maize, and rice have been analyzed, with significant yield improvements reported: 20-55% for wheat, 20-35% for potato, 20-40% for maize, and 13-25% for rice. Additionally, grain yield enhancements of 20-55% for wheat, 22-50% for maize, and 30-40% for rice have been observed. It has been emphasized that the optimization of nano-fertilizer concentrations and application methods is crucial to ensure plant health and environmental safety. The transformative role of nano-fertilizers in advancing sustainable agriculture to address global food security challenges has been underscored.

Zinc-dependent mechanisms of reparative regeneration: Theoretical aspects and translational perspectives

2025-06-20

Светлана А. Лебедева , Pavel A. Galenko-Yaroshevsky , Б. А. Трофимов +7 more | Reviews on Clinical Pharmacology and Drug Therapy

Reparative regeneration (RR) is a complex process of cells and tissue renewal after damage. Understanding of molecular mechanisms underlying RR is essential for identification of therapeutic strategies towards improving the … Reparative regeneration (RR) is a complex process of cells and tissue renewal after damage. Understanding of molecular mechanisms underlying RR is essential for identification of therapeutic strategies towards improving the outcomes of tissue damage. Zinc is a key player in RR. Therefore, modulation of cellular zinc signaling receives increasing attention in pharmacology. In this context, original complexes of zinc with N-alkenylimidazoles generated in Russian Federation revealed substantial efficacy in wound healing and further pathological conditions associated with RR. These metal complexes demonstrated anti-hypoxic, antioxidant, anti-ulcerogenic, and analgetic effects along with high safety and bioavailability. Further preclinical and clinical development of these substances bear substantial translational potential. The present review work provides potential explanations for beneficial effects of the synthesized zinc complexes of N-alkenylimidazoles based on the current understanding of zinc-dependent molec ular pathways mediating cellular and systemic RR processes.

Evaluation of Properties and Bioactivity of Silver (Ag) Nanoparticles (NPs) Fabricated Using Nixtamalization Wastewater (Nejayote)

2025-06-20

A. Lira , Juan Antonio Lozano-Álvarez , Norma Angélica Chávez Vela +4 more | Clean Technologies

Nejayote (Nej), an effluent from nixtamalization process, has an alkaline pH and contains a high load of organic matter in suspension and dissolution, which makes it a highly polluting waste … Nejayote (Nej), an effluent from nixtamalization process, has an alkaline pH and contains a high load of organic matter in suspension and dissolution, which makes it a highly polluting waste when discharged directly into the environment. However, the sustainable reuse of this effluent is relevant since it contains high-value compounds (ferulic acid (FA)) with appropriate activity for the ecological synthesis of silver nanoparticles (AgNPs). This study explores the synthesis of AgNPs using Nej as a reducing and stabilizing agent and evaluates the antibacterial effectiveness of AgNPs against Escherichia coli (E. coli). The AgNPs under study possess excellent optical (UV-Vis) and structural properties (XRD). HR-TEM images show predominantly spherical particles, with an average size of 20 nm. FTIR spectroscopy identified functional groups, including phenols and flavonoids, on the nanoparticle surface, acting as stabilizing agents. HPLC supports the existence of FA in the AgNPs. Biogenic AgNPs exhibit enhanced antibacterial activity due to the adsorption of these functional groups onto their surface, which contributes to bacterial membrane disruption. Finally, no hemolytic or cytotoxic activity was observed, suggesting that the AgNPs exert antimicrobial activity without potentially harmful doses (biocompatibility). The study highlights the potential of Nej as a sustainable source for use in nanoparticle synthesis, promoting the recycling of agro-industrial waste and the production of materials with technological applications.

Green Synthesis of ZnO@SiO2, CuO@SiO2, and Al₂O₃@SiO2 Nanocomposites Using Calligonum comosum L. Extract: Synthesis, Characterization, Photocatalysis, and Antioxidant Applications

2025-06-20

A. Gharbi , Hadia Hemmami , Salah Eddine Laouini +5 more | Applied Organometallic Chemistry

ABSTRACT Addressing the challenge of removing toxic pollutants and pathogens from water, this study explores the synthesis and performance of shell–core bimetallic oxide nanocomposites (ZnO@SiO 2 , CuO@SiO 2 , … ABSTRACT Addressing the challenge of removing toxic pollutants and pathogens from water, this study explores the synthesis and performance of shell–core bimetallic oxide nanocomposites (ZnO@SiO 2 , CuO@SiO 2 , Al 2 O 3 @SiO 2 ) alongside individual nanoparticles (ZnO, CuO, Al 2 O 3 , SiO 2 ). A green synthesis approach utilizing Calligonum comosum L. extract was employed, followed by characterization using UV–Visible spectroscopy, FTIR, XRD, and SEM. The band gap energies of the shell–core nanocomposites were significantly reduced compared to their individual counterparts (ZnO@SiO 2 : 2.15 eV, CuO@SiO 2 : 1.06 eV, Al 2 O 3 @SiO 2 : 1.80 eV) versus (ZnO: 2.30 eV, CuO: 1.42 eV, Al 2 O 3 : 2.50 eV). These reductions, combined with smaller crystallite sizes, contributed to improved optical and structural properties. Photocatalytic efficiency was tested with Methylene Blue (MB) and Rose Bengal (RB) dyes. Nanocomposites outperformed pure oxides, achieving MB degradation of 99.3% (ZnO@SiO 2 ), 97.57% (CuO@SiO 2 ), and 99.2% (Al 2 O 3 @SiO 2 ), and RB degradation of 98.0%, 84.8%, and 92.4%, respectively. SiO 2 enhanced surface area, charge separation, and reduced electron–hole recombination and agglomeration, improving stability. Antioxidant activity, via DPPH assay, peaked in CuO nanoparticles (IC 50 = 0.1313 mg/mL), with further gains from SiO 2 . This shows the nanocomposites' superior photocatalytic and antioxidant performance, highlighting SiO 2 's synergistic role and potential for environmental and biomedical uses.

Investigation of Inhibition Effect on Pathogen Microorganisms by Adding NPAg to Activated Carbon Obtained by Activating Hazelnut Shell with ZnCl2

2025-06-19

Birsen Sarıcı , Esra Altıntığ , Şükrü Karataş | Sakarya University Journal of Science

In this study, silver-coated activated carbon (NPAgAC) was obtained by adding nanoparticle silver (NPAg) to activated carbon (AC) produced from hazelnut shells by chemical activation and carbonization. SEM, FT-IR, and … In this study, silver-coated activated carbon (NPAgAC) was obtained by adding nanoparticle silver (NPAg) to activated carbon (AC) produced from hazelnut shells by chemical activation and carbonization. SEM, FT-IR, and BET were evaluated. While the methylene blue (MB) number of the produced ACs was 490-499 mg/g, the MB numbers of NPAgAC were determined to be 421-453 mg/g. The iodine number of ACs was specified in the 1047-1612 mg/g range. The iodine numbers of NPAgACs were recorded in the 934-1022 mg/ g range. Additionally, EDS and XRD analyses were performed on all samples. Well, diffusion and spreading plate methods were used to control the antimicrobial properties of the produced NPAgAC. The study used Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as pathogenic microorganisms. In addition, the antimicrobial properties of NPAgACs were investigated using the spread plate method at various times and temperatures to determine their effectiveness in inhibiting the growth of E. coli in polluted waters. Studies have shown that hazelnut shells are a suitable starting material for producing activated carbon, and that NPAgAC exhibits high antimicrobial properties with food safety.

Copper Nanoparticles in Aquatic Environment: Release Routes and Oxidative Stress-Mediated Mechanisms of Toxicity to Fish in Various Life Stages and Future Risks

2025-06-19

Anna Sielska , Lidia Skuza | Current Issues in Molecular Biology

The final recipient of nanoparticles, including various types of copper-based nanoparticles (Cu-based NPs), is the aquatic environment. Their increased production, especially as a component of antimicrobial agents, raises concerns about … The final recipient of nanoparticles, including various types of copper-based nanoparticles (Cu-based NPs), is the aquatic environment. Their increased production, especially as a component of antimicrobial agents, raises concerns about uncontrolled environmental release and subsequent ecological risks. The high reactivity of Cu-based NPs enables interactions with biotic and abiotic environmental components, leading to bioaccumulation and disorders in living organisms, such as fish in various life stages, especially in embryos or hatchlings. Increasing concentration of Cu-based NPs causes various toxic effects, mainly through the induction of oxidative stress. These effects include impairment of antioxidant mechanisms, as well as damage to genetic material, cells and tissues, growth retardation, metabolic disorders, increased mortality, or hatching inhibition. The aim of this review is to describe the release routes of Cu-based NPs and their adverse effects on fish, while emphasizing the need for further research on their toxicity and measures to control their release to the environment. Given the limited data on the toxicity of Cu-based NPs, especially concerning sensitive fish developmental stages, further studies are required.

Toxicity and genotoxicity of green iron oxide nanoparticles conjugated with bovine serum albumin against colorectal HT29 and HCT116 cancer cells

2025-06-19

Norul Aini Zakariya , Shahnaz Majeed , Nor Adzimah Johdi +4 more | Journal of Sol-Gel Science and Technology

Relative biodistribution and accumulation of carbonaceous nanoparticles inside the murine and human kidney

2025-06-19

Leen Rasking , Kenneth Vanbrabant , Maartje Vangeneugden +6 more | Journal of Hazardous Materials Advances

Green synthesis of silver nanoparticles using Argyreia pilosa leaf extract: Characterization and bioactivity assessment

2025-06-19

Kapil V. Shinde , Aditya B. Magdum , Mahesh P. Mane +5 more | Next Materials

Ecotoxicology of Mercerized Cellulose–Treated Tannery Effluents Using <scp>Salvinia auriculata</scp> (Salviniaceae) as a Bioindicator

2025-06-19

Alex Rodrigues Gomes , Letícia Paiva de Matos , Abner Marcelino Silva +7 more | Environmental Toxicology

ABSTRACT Given the growing concern over the environmental impacts of industrial effluents, particularly from tanneries, assessing the ecotoxicological risks associated with these effluents, even after remediation treatments, is crucial. Therefore, … ABSTRACT Given the growing concern over the environmental impacts of industrial effluents, particularly from tanneries, assessing the ecotoxicological risks associated with these effluents, even after remediation treatments, is crucial. Therefore, we aimed to evaluate the potential effects of exposure to raw and treated tannery effluents with mercerized microcrystalline cellulose particles (MCPs) on Salvinia auriculata . This study addresses the need for sustainable treatment alternatives that can reduce toxicity while assessing the residual impacts on aquatic plants. Plants were exposed to effluent dilutions (0.3% and 3.1%) for 15 days under controlled conditions. Biomarkers related to growth, photosynthesis (chlorophyll a , b , and total), oxidative stress (ROS, MDA, nitrite), and antioxidant enzyme activities (SOD, CAT, and SOD/CAT ratio) were analyzed. Although MCPs reduced chromium concentrations, treated effluents still caused significant toxicity, with root growth inhibition reaching 40% and chlorophyll a decreasing by over 30%. Principal Component Analysis (PCA) and Cluster Analysis revealed clear group separation, driven by Cr accumulation and changes in key physiological and biochemical markers. These findings highlight the partial effectiveness of MCPs and the importance of including ecotoxicological endpoints when evaluating treatment technologies. Although MCPs represent a promising step toward environmentally friendly remediation, further optimization is needed to reduce residual toxicity and assess long‐term and multispecies effects. The study also reinforces the utility of aquatic macrophytes as sentinel organisms in environmental monitoring and supports the development of more robust effluent management strategies that integrate both chemical and biological evaluations.

Impacts of Cerium Dioxide Nanoparticles on the Soil–Plant System and Their Potential Agricultural Applications

2025-06-19

Nadeesha Ukwattage , Zhiyong Zhang | Nanomaterials

Cerium dioxide nanoparticles (CeO2-NPs) are increasingly used in various industrial applications, leading to their inevitable release into the environment including the soil ecosystem. In soil, CeO2-NPs are taken up by … Cerium dioxide nanoparticles (CeO2-NPs) are increasingly used in various industrial applications, leading to their inevitable release into the environment including the soil ecosystem. In soil, CeO2-NPs are taken up by plants, translocated, and accumulated in plant tissues. Within plant tissues, CeO2-NPs have been shown to interfere with critical metabolic pathways, which may affect plant health and productivity. Moreover, their presence in soil can influence soil physico-chemical and biological properties, including microbial communities within the rhizosphere, where they can alter microbial physiology, diversity, and enzymatic activities. These interactions raise concerns about the potential disruption of plant-microbe symbiosis essential for plant nutrition and soil health. Despite these challenges, CeO2-NPs hold potential as tools for enhancing crop productivity and resilience to stress, such as drought or heavy metal contamination. However, understanding the balance between their beneficial and harmful effects is crucial for their safe application in agriculture. To date, the overall impact of CeO2-NPs on soil -plant system and the underlying mechanism remains unclear. Therefore, this review analyses the recent research findings to provide a comprehensive understanding of the fate of CeO2-NPs in soil-plant systems and the implications for soil health, plant growth, and agricultural productivity. As the current research is limited by inconsistent findings, often due to variations in experimental conditions, it is essential to study CeO2-NPs under more ecologically relevant settings. This review further emphasizes the need for future research to assess the long-term environmental impacts of CeO2-NPs in soil-plant systems and to develop guidelines for their responsible use in sustainable agriculture.

Phytolacca dodecandra leaf extract mediated synthesis of copper-doped zinc oxide nanoparticle and its application for methylen blue dye degradation

2025-06-19

Gemechu Dufera Abebe , Shibiru Yadeta Ejeta | Results in Chemistry

Polysaccharides from Agro-Industrial Waste and By-Products: An Overview on Green Synthesis of Metallic Nanoparticles—An Ecofriendly Approach

2025-06-19

Frida Lourdes García-Larez , Ariel Alain Vergel-Alfonso , Hylse Aurora Ruiz-Velducea +7 more | Polysaccharides

This review explores the eco-friendly synthesis of metallic nanoparticles derived from polysaccharides obtained from agricultural and food industry waste. Initially, it outlines the problem of agri-food waste, highlighting its abundance … This review explores the eco-friendly synthesis of metallic nanoparticles derived from polysaccharides obtained from agricultural and food industry waste. Initially, it outlines the problem of agri-food waste, highlighting its abundance and the potential to extract valuable polysaccharides such as cellulose, hemicellulose, lignin, and pectin. The focus is on green synthesis methods that use these polysaccharides to produce metallic nanoparticles, emphasizing the environmental benefits compared to conventional methods. The article reviews the physicochemical properties of key polysaccharides and details their extraction processes from various agricultural waste. The synthesis of diverse types of metallic nanoparticles, including monometallic (e.g., gold, silver, and platinum), bimetallic (e.g., gold–silver and gold–zinc), and oxide nanoparticles (e.g., zinc oxide and iron oxide), is extensively covered. Additionally, mechanisms of nanoparticle synthesis, such as nucleation, growth, stabilization, and capping, are examined, alongside examples from existing research. The article highlights the applications of these nanoparticles in diverse fields, including food safety, healthcare, agriculture, and environmental protection. It concludes by underscoring the potential of green synthesis to reduce waste and promote sustainable industrial practices and calls for further research to optimize these methods.

Treatment of <scp>Pseudomonas aeruginosa</scp>–Induced Lung Infection Using Iron Nanoparticles Green‐Formulated by <scp>Syzygium aromaticum</scp> Leaf Aqueous Extract

2025-06-19

Guangjun Wang , Baogang Wang , Luoping Yin | Applied Organometallic Chemistry

ABSTRACT Due mostly to the relative lack of effective chemotherapeutic methods, the lung infections' incidence caused by Pseudomonas aeruginosa categorized as multi‐drug resistant has significantly increased. This study demonstrated the … ABSTRACT Due mostly to the relative lack of effective chemotherapeutic methods, the lung infections' incidence caused by Pseudomonas aeruginosa categorized as multi‐drug resistant has significantly increased. This study demonstrated the strong antioxidant and anti‐infectious properties of iron nanoparticles prepared using a Syzygium aromaticum aqueous extract in vivo. We employed UV–Vis, FE‐SEM, XRD, FT‐IR, and TEM to determine the characteristics of the iron nanoparticles (FeNPs) that were created when an iron salt solution and aqueous S. aromaticum extract reacted. The existence of metallic iron nano crystallites that were absorbed by the SPR of the FeNPs was suggested by the energy dispersive spectra, which displayed strong spectrum peaks corresponding to Fe at 7.13, 6.44, and 0.71 keV. The signals are indexed as (311), (400), and (440) planes with 2θ values of 38.3, 44.3, and 64.5. The size range of the produced Ag NPs was usually 25–35 nm. The fatal dosage of P. aeruginosa is assessed in Swiss albino mice as part of an in vivo investigation, and the clinical manifestations—such as bacteremia, hypothermia, and weight loss—are analyzed 48 h after infection. Infected mice's physical manifestations revealed a 20% weight loss after the trial and a considerable drop in body temperature, from 38.7°C (0 h) to 34.6°C (after 48 h). Furthermore, using bacteremia, histology, and radiological examination, the effectiveness of FeNPs against lung infection caused by the projected fatal dose was assessed. On Day 7, the bacterial burden was 0.2 Log10CFU/mL in the FeNPs group, which was much lower than the bacterial burden on Day 1, which was 1.8 Log10CFU/mL. According to the study, 50 μg/kg of the FeNPs extract is effective against P. aeruginosa –induced lung infections. The goal of the current work was to build a powerful regimen against this dangerous infection by further using the biological features of FeNPs. Histopathological findings revealed infiltrates in every lung segment of infected mice, as well as a more widespread and patchy buildup of inflammatory cells inside the alveolar space.

Green One-Pot Synthesis of Silver and Gold Nanoparticles Using Catechin Extracts: Influence of Temperature and Antioxidant Activity Evaluation

2025-06-19

Gönül SERDAR , Gülşah Gül Kılınç , Tapas Sen | Plasmonics

Abstract In this study, gold (Au) and silver (Ag) nanoparticles were synthesized from an aqueous solution of catechin extract obtained by sequential microwave extraction (MAE) and supercritical fluid extraction (SFE) … Abstract In this study, gold (Au) and silver (Ag) nanoparticles were synthesized from an aqueous solution of catechin extract obtained by sequential microwave extraction (MAE) and supercritical fluid extraction (SFE) for the first time at different temperatures (25, 35, 45 °C) in accordance with the characteristics of green chemistry. For the synthesis of Ag and Au nanoparticles at three different temperatures, 100 mL of an aqueous 1 mM AgNO 3 solution was added to different volumes (0.5–4 mL) of catechin extract solutions. In the biosynthesis of Ag and Au nanoparticles, 1 mM AgNO 3 solution and 0.5 mM HAuCl 4 .3H 2 O at 25 °C and 0.5 mL extract volume were determined as the best parameters. The crystalline structures of AgNP and AuNP nanoparticles synthesized using catechin extract in accordance with green chemistry principles were confirmed by X-ray diffraction (XRD) analysis. The average crystallite sizes were determined to be 18.82 nm for AgNPs and 14.31 nm for AuNPs. Transmission electron microscopy (TEM) revealed size distributions of 19.50 ± 5.52 nm for AgNPs and 20.06 ± 5.38 nm for AuNPs. Dynamic light scattering (DLS) analysis showed that the hydrodynamic diameters were 37.61 ± 1.25 nm for AgNPs and 37.9 ± 0.26 nm for AuNPs. The zeta potential values were measured as –20.4 mV for AgNPs and –22.6 mV for AuNPs. The PDI (polydispersity index) values were found to be 0.271 ± 0.006 for AgNPs and 0.295 ± 0.004 for AuNPs. The effects of various concentrations of AgNPs and AuNPs on DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity were determined. At a concentration of 0.91 mg/mL, AgNPs exhibited a high antioxidant activity of 89.24%, while AuNPs showed 70.46% activity at 2.677 mg/mL. In comparison, the standard antioxidant Trolox demonstrated 91.19% inhibition at a concentration of 0.012 mg/mL. The IC₅₀ values of green-synthesized AgNPs, AuNPs, and standard Trolox were calculated as 1.151, 1.485, and 0.006 mg/mL, respectively. The results obtained from this study indicate that biologically synthesized AgNPs and AuNPs can be effectively used as potent antioxidants.