Materials Science › Biomaterials

Silk-based biomaterials and applications

Works Count: 31633

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Description

This cluster of papers focuses on the biomedical applications of silk biomaterials, particularly silk fibroin, in areas such as tissue engineering, drug delivery, and understanding the mechanical properties and protein structure of silk. It also covers topics related to spider silk and regenerated silk, as well as the genome sequencing and biodegradation of silk biomaterials.

Keywords

Silk Fibroin; Biomaterials; Tissue Engineering; Spider Silk; Regenerated Silk; Drug Delivery; Mechanical Properties; Genome Sequencing; Biodegradation; Protein Structure

Liquid crystalline spinning of spider silk

2001-03-01

Fritz Vollrath , David P. Knight

Structure and Properties of Silk Hydrogels

2004-03-18

Ung-Jin Kim , Jae Hyung Park , Chunmei Li +3 more

Control of silk fibroin concentration in aqueous solutions via osmotic stress was studied to assess relationships to gel formation and structural, morphological, and functional (mechanical) changes associated with this process. … Control of silk fibroin concentration in aqueous solutions via osmotic stress was studied to assess relationships to gel formation and structural, morphological, and functional (mechanical) changes associated with this process. Environmental factors potentially important in the in vivo processing of aqueous silk fibroin were also studied to determine their contributions to this process. Gelation of silk fibroin aqueous solutions was affected by temperature, Ca2+, pH, and poly(ethylene oxide) (PEO). Gelation time decreased with increase in protein concentration, decrease in pH, increase in temperature, addition of Ca2+, and addition of PEO. No change of gelation time was observed with the addition of K+. Upon gelation, a random coil structure of the silk fibroin was transformed into a β-sheet structure. Hydrogels with fibroin concentrations >4 wt % exhibited network and spongelike structures on the basis of scanning electron microscopy. Pore sizes of the freeze-dried hydrogels were smaller as the silk fibroin concentration or gelation temperature was increased. Freeze-dried hydrogels formed in the presence of Ca2+ exhibited larger pores as the concentration of this ion was increased. Mechanical compressive strength and modulus of the hydrogels increased with increase in protein concentration and gelation temperature. The results of these studies provide insight into the sol−gel transitions that silk fibroin undergoes in glands during aqueous processing while also providing important insight in the in vitro processing of these proteins into useful new materials.

Distortionless enhancement of NMR signals by polarization transfer

1982-06-01

David M. Doddrell , David T. Pegg , M.Robin Bendall

Stem cell-based tissue engineering with silk biomaterials

2006-08-08

Yongzhong Wang , Hyeon-Joo Kim , Gordana Vunjak‐Novakovic +1 more

Chitins and chitosans for the repair of wounded skin, nerve, cartilage and bone

2008-11-14

Riccardo A.A. Müzzarelli

In vivo degradation of three-dimensional silk fibroin scaffolds

2008-05-29

Yongzhong Wang , D. Rudym , Ashley Walsh +5 more

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New Opportunities for an Ancient Material

2010-07-29

Fiorenzo G. Omenetto , David L. Kaplan

Spiders and silkworms generate silk protein fibers that embody strength and beauty. Orb webs are fascinating feats of bioengineering in nature, displaying magnificent architectures while providing essential survival utility for … Spiders and silkworms generate silk protein fibers that embody strength and beauty. Orb webs are fascinating feats of bioengineering in nature, displaying magnificent architectures while providing essential survival utility for spiders. The unusual combination of high strength and extensibility is a characteristic unavailable to date in synthetic materials yet is attained in nature with a relatively simple protein processed from water. This biological template suggests new directions to emulate in the pursuit of new high-performance, multifunctional materials generated with a green chemistry and processing approach. These bio-inspired and high-technology materials can lead to multifunctional material platforms that integrate with living systems for medical materials and a host of other applications.

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Silver Staining of Myelin by Means of Physical Development

1979-01-01

Ferenc Gallyas

For staining myelin with silver a physical development technique has been devised that can render visible the thinnest fibers in various animal species, including fishes and reptiles, even in the … For staining myelin with silver a physical development technique has been devised that can render visible the thinnest fibers in various animal species, including fishes and reptiles, even in the early phase of myelination and may be applied to both frozen and embedded materials. Its principle is as follows: Myelin can form and bind colloidal silver particles in a 0.1% ammoniacal silver nitrate solution of pH 7.5. The production of metallic silver by other tissue elements is suppressed by the sections pretreated with a 2:1 mixture of pyridine and acetic anhydride for 30 min. The colloidal silver particles bound in the myelin are enlarged to microscopic dimensions by a special physical developer.

Current research on the blends of natural and synthetic polymers as new biomaterials: Review

2011-05-26

Alina Sionkowska

In vitro degradation of silk fibroin

2004-12-15

Rebecca L. Horan , Kathryn A. Antle , Adam L. Collette +6 more

Surprising strength of silkworm silk

2002-08-01

Zhengzhong Shao , Fritz Vollrath

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An investigation of the structure of silk fibroin

1955-01-01

R.E. Marsh , Robert B. Corey , Linus Pauling

Spider Silk Fibers Spun from Soluble Recombinant Silk Produced in Mammalian Cells

2002-01-18

Anthoula Lazaris , Steven Arcidiacono , Yue Huang +6 more

Spider silks are protein-based “biopolymer” filaments or threads secreted by specialized epithelial cells as concentrated soluble precursors of highly repetitive primary sequences. Spider dragline silk is a flexible, lightweight fiber … Spider silks are protein-based “biopolymer” filaments or threads secreted by specialized epithelial cells as concentrated soluble precursors of highly repetitive primary sequences. Spider dragline silk is a flexible, lightweight fiber of extraordinary strength and toughness comparable to that of synthetic high-performance fibers. We sought to “biomimic” the process of spider silk production by expressing in mammalian cells the dragline silk genes ( ADF-3 / MaSpII and MaSpI ) of two spider species. We produced soluble recombinant (rc)–dragline silk proteins with molecular masses of 60 to 140 kilodaltons. We demonstrated the wet spinning of silk monofilaments spun from a concentrated aqueous solution of soluble rc–spider silk protein (ADF-3; 60 kilodaltons) under modest shear and coagulation conditions. The spun fibers were water insoluble with a fine diameter (10 to 40 micrometers) and exhibited toughness and modulus values comparable to those of native dragline silks but with lower tenacity. Dope solutions with rc–silk protein concentrations >20% and postspinning draw were necessary to achieve improved mechanical properties of the spun fibers. Fiber properties correlated with finer fiber diameter and increased birefringence.

Electrospinning of silk fibroin nanofibers and its effect on the adhesion and spreading of normal human keratinocytes and fibroblasts in vitro

2003-10-16

Byung‐Moo Min , Gene Lee , Kim Ys +3 more

Silk as a biomaterial

2007-06-12

Charu Vepari , David L. Kaplan

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Collagen Tissue Engineering: Development of Novel Biomaterials and Applications

2008-04-14

Lian Cen , Wei Liu , Lei Cui +2 more

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Silk fibroin biomaterials for tissue regenerations

2012-11-05

Banani Kundu , Rangam Rajkhowa , Subhas C. Kundu +1 more

Polymers for the sustained release of proteins and other macromolecules

1976-10-28

Róbert Langer , Judah Folkman

Bio-inspired design of multiscale structures for function integration

2011-03-08

Kesong Liu , Lei Jiang

Materials fabrication from Bombyx mori silk fibroin

2011-09-22

Danielle N. Rockwood , Rucsanda C. Preda , Tuna Yücel +3 more

Structures, mechanical properties and applications of silk fibroin materials

2015-02-11

Leng‐Duei Koh , Yuan Cheng , Choon-Peng Teng +7 more

How does the extracellular matrix direct gene expression?

1982-11-01

Mina J. Bissell , H.Glenn Hall , Gordon Parry

Smooth muscle cell growth in photopolymerized hydrogels with cell adhesive and proteolytically degradable domains: synthetic ECM analogs for tissue engineering

2001-11-01

Brenda K. Mann , Andrea S. Gobin , Annabel T. Tsai +2 more

Mechanism of silk processing in insects and spiders

2003-08-01

Hyoung‐Joon Jin , David L. Kaplan

Incorporation of adhesion peptides into nonadhesive hydrogels useful for tissue resurfacing

1998-02-01

Diane L. Hern , Jeffrey A. Hubbell

Photopolymerized crosslinked networks of poly(ethylene glycol; PEG) diacrylate (MW 8000) were derivitized throughout their bulk with Arg-Gly-Asp (RGD)-containing peptide sequences. Incorporation was achieved by functionalizing the amine terminus of the … Photopolymerized crosslinked networks of poly(ethylene glycol; PEG) diacrylate (MW 8000) were derivitized throughout their bulk with Arg-Gly-Asp (RGD)-containing peptide sequences. Incorporation was achieved by functionalizing the amine terminus of the peptide with an acrylate moiety, thereby enabling the adhesion peptide to copolymerize rapidly with the PEG diacrylate upon photoinitiation. PEG diacrylate hydrogels derivitized with RGD peptide at surface concentrations ranging from 0.001 to 1 pmol/cm2 were studied in vitro for their ability to promote spreading of human foreskin fibroblasts over 24 h. Hydrogels not derivitized with peptides were poor substrates for adhesion, permitting spreading of only 5% of the seeded cells. When immobilized with no spacer arm, both RGD and RDG (inactive control) supported spreading of approximately 50% and approximately 15% of cells at 1 and 0.1 pmol/cm2 surface concentrations respectively; lower concentrations did not promote spreading. When a MW 3400 PEG spacer arm was incorporated between the hydrogel and the peptide linkage, incorporation of 1 pmol/cm2 RGD promoted 70% spreading whereas RDG at the same concentration did not promote spreading. In addition, when cells were seeded in serum-free medium, only RGD peptides incorporated with a spacer arm were able to promote spreading. Thus peptide incorporated into PEG 8000 diacrylate hydrogels without a spacer arm nonspecifically mediated cell spreading whereas incorporation via a MW 3400 PEG spacer arm was required to permit cell spreading to be specifically mediated.

SATELLITE CELL OF SKELETAL MUSCLE FIBERS

1961-02-01

Alexander Mauro

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Structure of a protein superfiber: spider dragline silk.

1990-09-01

Ming Xu , Randolph V. Lewis

Spider major ampullate (dragline) silk is an extracellular fibrous protein with unique characteristics of strength and elasticity. The silk fiber has been proposed to consist of pseudocrystalline regions of antiparallel … Spider major ampullate (dragline) silk is an extracellular fibrous protein with unique characteristics of strength and elasticity. The silk fiber has been proposed to consist of pseudocrystalline regions of antiparallel beta-sheet interspersed with elastic amorphous segments. The repetitive sequence of a fibroin protein from major ampullate silk of the spider Nephila clavipes was determined from a partial cDNA clone. The repeating unit is a maximum of 34 amino acids long and is not rigidly conserved. The repeat unit is composed of three different segments: (i) a 6 amino acid segment that is conserved in sequence but has deletions of 3 or 6 amino acids in many of the repeats; (ii) a 13 amino acid segment dominated by a polyalanine sequence of 5-7 residues; (iii) a 15 amino acid, highly conserved segment. The latter is predominantly a Gly-Gly-Xaa repeat with Xaa being alanine, tyrosine, leucine, or glutamine. The codon usage for this DNA is highly selective, avoiding the use of cytosine or guanine in the third position. A model for the physical properties of fiber formation, strength, and elasticity, based on this repetitive protein sequence, is presented.

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Porous 3-D Scaffolds from Regenerated Silk Fibroin

2004-01-23

Rina Nazarov , Hyoung‐Joon Jin , David L. Kaplan

Three fabrication techniques, freeze-drying, salt leaching and gas foaming, were used to form porous three-dimensional silk biomaterial matrixes. Matrixes were characterized for morphological and functional properties related to processing method … Three fabrication techniques, freeze-drying, salt leaching and gas foaming, were used to form porous three-dimensional silk biomaterial matrixes. Matrixes were characterized for morphological and functional properties related to processing method and conditions. The porosity of the salt leached scaffolds varied between 84 and 98% with a compressive strength up to 175 ± 3 KPa, and the gas foamed scaffolds had porosities of 87−97% and compressive strength up to 280 ± 4 KPa. The freeze-dried scaffolds were prepared at different freezing temperatures (−80 and −20 °C) and subsequently treated with different concentrations (15 and 25%) and hydrophilicity alcohols. The porosity of these scaffolds was up to 99%, and the maximum compressive strength was 30 ± 2 KPa. Changes in silk fibroin structure during processing to form the 3D matrixes were determined by FT-IR and XrD. The salt leached and gas foaming techniques produced scaffolds with a useful combination of high compressive strength, interconnected pores, and pore sizes greater than 100 microns in diameter. The results suggest that silk-based 3D matrixes can be formed for utility in biomaterial applications.

Elastic proteins: biological roles and mechanical properties

2002-02-28

John M. Gosline , M. A. Lillie , Emily Carrington +3 more

The term ‘elastic protein’ applies to many structural proteins with diverse functions and mechanical properties so there is room for confusion about its meaning. Elastic implies the property of elasticity, … The term ‘elastic protein’ applies to many structural proteins with diverse functions and mechanical properties so there is room for confusion about its meaning. Elastic implies the property of elasticity, or the ability to deform reversibly without loss of energy; so elastic proteins should have high resilience. Another meaning for elastic is ‘stretchy’, or the ability to be deformed to large strains with little force. Thus, elastic proteins should have low stiffness. The combination of high resilience, large strains and low stiffness is characteristic of rubber–like proteins (e.g. resilin and elastin) that function in the storage of elastic–strain energy. Other elastic proteins play very different roles and have very different properties. Collagen fibres provide exceptional energy storage capacity but are not very stretchy. Mussel byssus threads and spider dragline silks are also elastic proteins because, in spite of their considerable strength and stiffness, they are remarkably stretchy. The combination of strength and extensibility, together with low resilience, gives these materials an impressive resistance to fracture (i.e. toughness), a property that allows mussels to survive crashing waves and spiders to build exquisite aerial filters. Given this range of properties and functions, it is probable that elastic proteins will provide a wealth of chemical structures and elastic mechanisms that can be exploited in novel structural materials through biotechnology.

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Fine organization of Bombyx mori fibroin heavy chain gene

2000-06-15

Cong‐Zhao Zhou

The complete sequence of the Bombyx mori fibroin gene has been determined by means of combining a shotgun sequencing strategy with physical map-based sequencing procedures. It consists of two exons … The complete sequence of the Bombyx mori fibroin gene has been determined by means of combining a shotgun sequencing strategy with physical map-based sequencing procedures. It consists of two exons (67 and 15 750 bp, respectively) and one intron (971 bp). The fibroin coding sequence presents a spectacular organization, with a highly repetitive and G-rich (~45%) core flanked by non-repetitive 5′ and 3′ ends. This repetitive core is composed of alternate arrays of 12 repetitive and 11 amorphous domains. The sequences of the amorphous domains are evolutionarily conserved and the repetitive domains differ from each other in length by a variety of tandem repeats of subdomains of ~208 bp which are reminiscent of the repetitive nucleosome organization. A typical composition of a subdomain is a cluster of repetitive units, Ua, followed by a cluster of units, Ub, (with a Ua:Ub ratio of 2:1) flanked by conserved boundary elements at the 3′ end. Moreover some repeats are also perfectly conserved at the peptide level indicating that the evolutionary pressure is not identical along the sequence. A tentative model for the constitution and evolution of this unusual gene is discussed.

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Silk fibroin: Structural implications of a remarkable amino acid sequence

2001-05-25

Cong‐Zhao Zhou , Fabrice Confalonieri , Michel Jacquet +3 more

Abstract The amino acid sequence of the heavy chain of Bombyx mori silk fibroin was derived from the gene sequence. The 5,263‐residue (391‐kDa) polypeptide chain comprises 12 low‐complexity “crystalline” domains … Abstract The amino acid sequence of the heavy chain of Bombyx mori silk fibroin was derived from the gene sequence. The 5,263‐residue (391‐kDa) polypeptide chain comprises 12 low‐complexity “crystalline” domains made up of Gly–X repeats and covering 94% of the sequence; X is Ala in 65%, Ser in 23%, and Tyr in 9% of the repeats. The remainder includes a nonrepetitive 151‐residue header sequence, 11 nearly identical copies of a 43‐residue spacer sequence, and a 58‐residue C‐terminal sequence. The header sequence is homologous to the N‐terminal sequence of other fibroins with a completely different crystalline region. In Bombyx mori , each crystalline domain is made up of subdomains of ∼70 residues, which in most cases begin with repeats of the GAGAGS hexapeptide and terminate with the GAAS tetrapeptide. Within the subdomains, the Gly–X alternance is strict, which strongly supports the classic Pauling–Corey model, in which β‐sheets pack on each other in alternating layers of Gly/Gly and X/X contacts. When fitting the actual sequence to that model, we propose that each subdomain forms a β‐strand and each crystalline domain a two‐layered β‐sandwich, and we suggest that the β‐sheets may be parallel, rather than antiparallel, as has been assumed up to now. Proteins 2001;44:119–122. © 2001 Wiley‐Liss, Inc.

Silk Fibroin of Bombyx mori Is Secreted, Assembling a High Molecular Mass Elementary Unit Consisting of H-chain, L-chain, and P25, with a 6:6:1 Molar Ratio

2000-12-01

Satoshi Inoue , Kazunori Tanaka , Fumio Arisaka +3 more

Silk fibroin produced by the silkwormBombyx mori consists of a heavy chain, a light chain, and a glycoprotein, P25. The heavy and light chains are linked by a disulfide bond, … Silk fibroin produced by the silkwormBombyx mori consists of a heavy chain, a light chain, and a glycoprotein, P25. The heavy and light chains are linked by a disulfide bond, and P25 associates with disulfide-linked heavy and light chains by noncovalent interactions. Quantitative enzyme-linked immunosorbent assay revealed that molar ratios of the heavy chain, light chain, and P25 were 6:6:1, both in cocoons and in fibroin secreted into the lumen of posterior silk gland. Trace amounts of fibroin produced by three "naked pupa" mutants of B. mori lacked the light chain, but the molar ratio of heavy chain and P25 was also 6:1. Gel filtration chromatography and sedimentation equilibrium analysis demonstrated that a large protein complex of approximately 2.3 MDa, designated an elementary unit of fibroin having 6:6:1 molar ratios of the heavy chain, light chain, and P25, existed in posterior silk gland cells. Inaccessibility of biotinylated concanavalin A to the native elementary unit and partial dissociation of the elementary unit after incubation with excess N-glycosidase F or endoglycosidase H suggest that a single molecule of P25 is located internally and plays an important role in maintaining integrity of the complex.

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Barrel-Stave Model or Toroidal Model? A Case Study on Melittin Pores

2001-09-01

Lin Yang , Thad A. Harroun , Thomas Weiß +2 more

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Natural fibre-reinforced composites for bioengineering and environmental engineering applications

2009-04-22

Hoi‐Yan Cheung , Mei-po Ho , Kin-tak Lau +2 more

Silk matrix for tissue engineered anterior cruciate ligaments

2002-10-01

Gregory H. Altman , Rebecca L. Horan , Helen H. Lu +4 more

Macrophages are required for adult salamander limb regeneration

2013-05-20

James W. Godwin , Alexander R. Pinto , Nadia Rosenthal

The failure to replace damaged body parts in adult mammals results from a muted growth response and fibrotic scarring. Although infiltrating immune cells play a major role in determining the … The failure to replace damaged body parts in adult mammals results from a muted growth response and fibrotic scarring. Although infiltrating immune cells play a major role in determining the variable outcome of mammalian wound repair, little is known about the modulation of immune cell signaling in efficiently regenerating species such as the salamander, which can regrow complete body structures as adults. Here we present a comprehensive analysis of immune signaling during limb regeneration in axolotl, an aquatic salamander, and reveal a temporally defined requirement for macrophage infiltration in the regenerative process. Although many features of mammalian cytokine/chemokine signaling are retained in the axolotl, they are more dynamically deployed, with simultaneous induction of inflammatory and anti-inflammatory markers within the first 24 h after limb amputation. Systemic macrophage depletion during this period resulted in wound closure but permanent failure of limb regeneration, associated with extensive fibrosis and disregulation of extracellular matrix component gene expression. Full limb regenerative capacity of failed stumps was restored by reamputation once endogenous macrophage populations had been replenished. Promotion of a regeneration-permissive environment by identification of macrophage-derived therapeutic molecules may therefore aid in the regeneration of damaged body parts in adult mammals.

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The inflammatory responses to silk films in vitro and in vivo

2004-04-10

Lorenz Meinel , Sandra Hofmann , Vassilis Karageorgiou +7 more

Silk-based biomaterials

2002-11-04

Gregory H. Altman , Frank Diaz , Caroline M. Jakuba +6 more

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The mechanical design of spider silks: from fibroin sequence to mechanical function

1999-12-01

John M. Gosline , Paul A. Guerette , Christine Ortlepp +1 more

ABSTRACT Spiders produce a variety of silks, and the cloning of genes for silk fibroins reveals a clear link between protein sequence and structure–property relationships. The fibroins produced in the … ABSTRACT Spiders produce a variety of silks, and the cloning of genes for silk fibroins reveals a clear link between protein sequence and structure–property relationships. The fibroins produced in the spider’s major ampullate (MA) gland, which forms the dragline and web frame, contain multiple repeats of motifs that include an 8–10 residue long poly-alanine block and a 24–35 residue long glycine-rich block. When fibroins are spun into fibres, the poly-alanine blocks form β-sheet crystals that crosslink the fibroins into a polymer network with great stiffness, strength and toughness. As illustrated by a comparison of MA silks from Araneus diadematus and Nephila clavipes, variation in fibroin sequence and properties between spider species provides the opportunity to investigate the design of these remarkable biomaterials.

Nanoconfinement controls stiffness, strength and mechanical toughness of β-sheet crystals in silk

2010-03-14

Sinan Keten , Zhi Ping Xu , Britni Ihle +1 more

Three-dimensional aqueous-derived biomaterial scaffolds from silk fibroin

2004-09-14

Ung‐Jin Kim , Jae Hyung Park , Hyeon Joo Kim +2 more

Photocrosslinkable Gelatin Hydrogel for Epidermal Tissue Engineering

2015-04-16

Xin Zhao , Qi Lang , Lara Yildirimer +7 more

Natural hydrogels are promising scaffolds to engineer epidermis. Currently, natural hydrogels used to support epidermal regeneration are mainly collagen‐ or gelatin‐based, which mimic the natural dermal extracellular matrix but often … Natural hydrogels are promising scaffolds to engineer epidermis. Currently, natural hydrogels used to support epidermal regeneration are mainly collagen‐ or gelatin‐based, which mimic the natural dermal extracellular matrix but often suffer from insufficient and uncontrollable mechanical and degradation properties. In this study, a photocrosslinkable gelatin (i.e., gelatin methacrylamide (GelMA)) with tunable mechanical, degradation, and biological properties is used to engineer the epidermis for skin tissue engineering applications. The results reveal that the mechanical and degradation properties of the developed hydrogels can be readily modified by varying the hydrogel concentration, with elastic and compressive moduli tuned from a few kPa to a few hundred kPa, and the degradation times varied from a few days to several months. Additionally, hydrogels of all concentrations displayed excellent cell viability (>90%) with increasing cell adhesion and proliferation corresponding to increases in hydrogel concentrations. Furthermore, the hydrogels are found to support keratinocyte growth, differentiation, and stratification into a reconstructed multilayered epidermis with adequate barrier functions. The robust and tunable properties of GelMA hydrogels suggest that the keratinocyte laden hydrogels can be used as epidermal substitutes, wound dressings, or substrates to construct various in vitro skin models.

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Functionalized silk-based biomaterials for bone formation

2000-01-01

S. Sofia , Mary Beth McCarthy , Gloria Gronowicz +1 more

Silks are being reassessed as biomaterial scaffolds due to their unique mechanical properties, opportunities for genetic tailoring of structure and thus function, and recent studies clarifying biocompatibility. We report on … Silks are being reassessed as biomaterial scaffolds due to their unique mechanical properties, opportunities for genetic tailoring of structure and thus function, and recent studies clarifying biocompatibility. We report on the covalent decoration of silk films with integrin recognition sequences (RGD) as well as parathyroid hormone (PTH, 1-34 amino acids) and a modified PTH 1-34 (mPTH) involved in the induction of bone formation. Osteoblast-like cell (Saos-2) responses to the decorated silk films indicate that the proteins serve as suitable bone-inducing matrices. Osteoblast-like cell adhesion was significantly increased on RGD and PTH compared to plastic, mPTH, and the control peptide RAD. At 2 weeks of culture, message levels of alkaline phosphatase were similar on all substrates, but by 4 weeks, alkaline phosphatase mRNA was greatest on RGD. At 2 weeks of culture, alpha 1(I) procollagen mRNA was elevated on silk, RGD, RAD, and PTH, and hardly detectable on mPTH and plastic. However, by 4 weeks RGD demonstrated the highest level compared to the other substrates. Osteocalcin message levels detected by RT-PCR were greatest on RGD at both time points. Calcification was also significantly elevated on RGD compared to the other substrates with an increase in number and size of the mineralized nodules in culture. Thus, RGD covalently decorated silk appears to stimulate osteoblast-based mineralization in vitro.

Hydrogels in Regenerative Medicine

2009-07-18

Brandon V. Slaughter , Shahana S. Khurshid , Omar Z. Fisher +2 more

Hydrogels, due to their unique biocompatibility, flexible methods of synthesis, range of constituents, and desirable physical characteristics, have been the material of choice for many applications in regenerative medicine. They … Hydrogels, due to their unique biocompatibility, flexible methods of synthesis, range of constituents, and desirable physical characteristics, have been the material of choice for many applications in regenerative medicine. They can serve as scaffolds that provide structural integrity to tissue constructs, control drug and protein delivery to tissues and cultures, and serve as adhesives or barriers between tissue and material surfaces. In this work, the properties of hydrogels that are important for tissue engineering applications and the inherent material design constraints and challenges are discussed. Recent research involving several different hydrogels polymerized from a variety of synthetic and natural monomers using typical and novel synthetic methods are highlighted. Finally, special attention is given to the microfabrication techniques that are currently resulting in important advances in the field.

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Silk fibroin as biomaterial for bone tissue engineering

2015-09-07

J. Melke , Swati Midha , Sourabh Ghosh +2 more

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Tough bonding of hydrogels to diverse non-porous surfaces

2015-11-09

Hyunwoo Yuk , Teng Zhang , Shaoting Lin +2 more

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Electrospinning Bombyx mori Silk with Poly(ethylene oxide)

2002-08-28

Hyoung‐Joon Jin , Sergey V. Fridrikh , Gregory C. Rutledge +1 more

Electrospinning for the formation of nanoscale diameter fibers has been explored for high-performance filters and biomaterial scaffolds for vascular grafts or wound dressings. Fibers with nanoscale diameters provide benefits due … Electrospinning for the formation of nanoscale diameter fibers has been explored for high-performance filters and biomaterial scaffolds for vascular grafts or wound dressings. Fibers with nanoscale diameters provide benefits due to high surface area. In the present study we explore electrospinning for protein-based biomaterials to fabricate scaffolds and membranes from regenerated silkworm silk, Bombyx mori, solutions. To improve processability of the protein solution, poly(ethylene oxide) (PEO) with molecular weight of 900 000 was blended with the silk fibroin. A variety of compositions of the silk/PEO aqueous blends were successfully electrospun. The morphology of the fibers was characterized using high-resolution scanning electron microscopy. Fiber diameters were uniform and less than 800 nm. The composition was estimated by X-ray photoelectron spectroscopy to characterize silk/PEO surface content. Aqueous-based electrospining of silk and silk/PEO blends provides potentially useful options for the fabrication of biomaterial scaffolds based on this unique fibrous protein.

Determining Beta-Sheet Crystallinity in Fibrous Proteins by Thermal Analysis and Infrared Spectroscopy

2006-08-11

Xiao Hu , David L. Kaplan , Peggy Cebe

We report a study of self-assembled beta-pleated sheets in B. mori silk fibroin films using thermal analysis and infrared spectroscopy. B. mori silk fibroin may stand as an exemplar of … We report a study of self-assembled beta-pleated sheets in B. mori silk fibroin films using thermal analysis and infrared spectroscopy. B. mori silk fibroin may stand as an exemplar of fibrous proteins containing crystalline beta-sheets. Materials were prepared from concentrated solutions (2−5 wt % fibroin in water) and then dried to achieve a less ordered state without beta-sheets. Crystallization of beta-pleated sheets was effected either by heating the films above the glass transition temperature (Tg) and holding isothermally or by exposure to methanol. The fractions of secondary structural components including random coils, alpha-helices, beta-pleated sheets, turns, and side chains were evaluated using Fourier self-deconvolution (FSD) of the infrared absorbance spectra. The silk fibroin films were studied thermally using temperature-modulated differential scanning calorimetry (TMDSC) to obtain the reversing heat capacity. The increment of the reversing heat capacity ΔCp0(Tg) at the glass transition for the less ordered, noncrystalline, silk fibroin is found to be 0.478 ± 0.005 J/(g K). As crystalline beta-sheets form, the heat capacity increment at Tg is systematically decreased. We find that the heat capacity increment from the TMDSC trace is linearly well correlated (negatively) with beta-sheet content φC determined from FSD, yielding ΔCp = 0.475−0.494φC. The correlation allows the beta-sheet content to be determined from a direct measurement of the heat capacity increment at Tg. This type of analysis can serve as an alternative to X-ray methods and may have wide applicability to other crystalline beta-sheet forming proteins.

The Biomedical Use of Silk: Past, Present, Future

2018-09-20

Chris Holland , Keiji Numata , Jelena Rnjak‐Kovacina +1 more

Abstract Humans have long appreciated silk for its lustrous appeal and remarkable physical properties, yet as the mysteries of silk are unraveled, it becomes clear that this outstanding biopolymer is … Abstract Humans have long appreciated silk for its lustrous appeal and remarkable physical properties, yet as the mysteries of silk are unraveled, it becomes clear that this outstanding biopolymer is more than a high‐tech fiber. This progress report provides a critical but detailed insight into the biomedical use of silk. This journey begins with a historical perspective of silk and its uses, including the long‐standing desire to reverse engineer silk. Selected silk structure–function relationships are then examined to appreciate past and current silk challenges. From this, biocompatibility and biodegradation are reviewed with a specific focus of silk performance in humans. The current clinical uses of silk (e.g., sutures, surgical meshes, and fabrics) are discussed, as well as clinical trials (e.g., wound healing, tissue engineering) and emerging biomedical applications of silk across selected formats, such as silk solution, films, scaffolds, electrospun materials, hydrogels, and particles. The journey finishes with a look at the roadmap of next‐generation recombinant silks, especially the development pipeline of this new industry for clinical use.

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Keratin: Structure, mechanical properties, occurrence in biological organisms, and efforts at bioinspiration

2015-07-05

Bin Wang , Wen Yang , Joanna McKittrick +1 more

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Skin's 'nano-shield' hydrogel: Co-delivery of myricetin-laurate nanoagents eliminates fungus and promotes skin regeneration

2025-06-25

Lei Zhang , Kailai Liu , Jiachen Zhou +7 more | Bioactive Materials

In vivo study of naringin-loaded biomaterials patch coupled with biosensors for diabetic foot ulcer management

2025-06-24

Michael Michael , Eko Adi Prasetyanto | International Journal of Basic & Clinical Pharmacology

Background: Diabetic foot ulcers (DFUs) are a severe complication of diabetes, often leading to prolonged hospitalizations and even amputations. The need for advanced, efficient treatments is critical, particularly in regions … Background: Diabetic foot ulcers (DFUs) are a severe complication of diabetes, often leading to prolonged hospitalizations and even amputations. The need for advanced, efficient treatments is critical, particularly in regions like Indonesia, where healthcare resources are limited. In this study, naringin, a bioactive flavonoid renowned for its antioxidant and anti-inflammatory properties, was embedded within a biocompatible matrix of alginate, mesoporous silica, and polyvinyl alcohol. Methods: This patch was engineered using electrospinning techniques, ensuring a controlled release of naringin to the wound site. To further advance this treatment modality, a colorimetric biosensor targeting uric acid a critical biomarker of wound severity was seamlessly integrated into the patch. In vivo studies were conducted using diabetic mouse models to assess the patch's efficacy in promoting wound healing. Results: The results were promising: the naringin-loaded patches significantly accelerated wound closure and improved tissue regeneration compared to standard treatments. However, while the concept of integrating biosensors showed promise, the biosensor component in this study did not perform optimally and requires further refinement. The current iteration of the biosensor provided limited real-time monitoring capability, indicating the need for enhanced sensitivity and reliability for the application in the wound environment. This study highlights the potential of naringin-infused biomaterials as a therapeutic option for DFU treatment and underscores the importance of ongoing research to optimize biosensor integration. Conclusions: While the in vivo results are promising, the study calls for further development of biosensors to fully realize the potential of this combined approach in clinical settings.

Mucoadhesive Silk Fibroin Nanoparticles for Drug Delivery to the Ocular Surface

2025-06-24

Chula Srikajorn , Waree Tiyaboonchai , Sangly P. Srinivas +1 more | Journal of Ocular Pharmacology and Therapeutics

Purpose: To develop silk fibroin nanoparticles (SFNs) for prolonged drug delivery to the ocular surface. Methods: SFNs were prepared using nanoprecipitation, coated with chitosan (CS; positively charged), and stabilized with … Purpose: To develop silk fibroin nanoparticles (SFNs) for prolonged drug delivery to the ocular surface. Methods: SFNs were prepared using nanoprecipitation, coated with chitosan (CS; positively charged), and stabilized with polyethylene glycol 400. Their morphology, particle size distribution, and surface charge were analyzed using dynamic light scattering. Fourier transform infrared (FTIR) spectroscopy assessed the intermolecular interactions between CS and silk fibroin. The entrapment efficiencies (EE) for sodium fluorescein (NaF) and Nile Red (NR), which served as hydrophilic and hydrophobic drug surrogates, respectively, were determined. The mucoadhesiveness of SFNs was examined ex vivo with freshly isolated porcine eyes. Cellular uptake and cytotoxicity were evaluated in a human corneal epithelium cell line (HCEC). Results: SFNs were spherical, measuring 198.47 ± 35.54 nm in diameter, and had a surface charge of 38.33 ± 0.67 mV. The coating of CS on SFNs resulted in a peak shift in the amide group in the FTIR spectrum. The maximum EEs for NaF and NR in SFNs were approximately 95% and 67%, respectively. SFNs exhibited prolonged mucoadhesion on corneas for over 240 min and were rapidly endocytosed by HCEC in less than 30 min without inducing cytotoxicity. Conclusion: The properties of SFNs are suitable for delivering drugs to the ocular surface.

Bioactive Glass Incorporated Silk-Gelatin Composite Scaffold for Bone Tissue Engineering

2025-06-24

Radhakrishna Prabhu | International Journal of Oral and Maxillofacial Surgery

Silk Fibroin and Bioglass Composite as Bone

2025-06-24

R. Prabhu | International Journal of Oral and Maxillofacial Surgery

Bio-design material as scaffold module proposed to surgical application in osteoarthritis: fabrication, characterization, biological evaluation of in vitro testing

2025-06-24

Atsadaporn Thangprasert , Anne Bernhardt , Elke Gossla +6 more | Biomedical Materials

Abstract Treatment of osteochondral defects is a major topic of current research and becomes more important in an aging society. The challenges in bone and cartilage repair arise from structure … Abstract Treatment of osteochondral defects is a major topic of current research and becomes more important in an aging society. The challenges in bone and cartilage repair arise from structure and function of these different tissues. This study proposes a biphasic model combining cartilage and bone scaffolds based on silk fibroin (SF) biopolymers. For cartilage phase, SF scaffolds were coated with gelatin and/or agarose layers. For bone scaffolds, mineralized collagen solutions were coated on or mixed into the SF matrix. The physical and biological properties of these samples were evaluated to find the optimum conditions for a biphasic scaffold. Modification of both cartilage and bone scaffolds resulted in smaller pore size, lower swelling rate and higher rigidity. Gelatin significantly promoted cartilage biomarker production and agarose facilitated cell proliferation, inducing a homogenous cell distribution, and stimulating chondrogenesis. Furthermore, modification with mineralized collagen decreased cell proliferation in osteoblast progenitors but enhanced differentiation into osteoblasts. The optimum conditions were found at a mixture of gelatin and agarose for coating in case of cartilage phase and low mineralized collagen content for bone phase.

Longer Duct, Better Silk: Unveiling How Anterior Silk Gland Length Boosts Fiber Performance

2025-06-23

Qing Huang , Xiao Hu , Xinyu Fan +7 more | Biomacromolecules

The mechanical performance of silk is closely tied to the fibrillization process within the anterior segment of silk gland (ASG). While a long and narrow ASG is conserved across silk-spinning … The mechanical performance of silk is closely tied to the fibrillization process within the anterior segment of silk gland (ASG). While a long and narrow ASG is conserved across silk-spinning species, its biological role remains unclear. Here, we performed a comprehensive structure-function analysis of the silkworm ASG and revealed that its long and narrow morphology plays an essential role in silk fibrillization and fiber performance. A steep reduction in duct diameter at the ASG's onset initiates silk protein transformation, while the extended duct length promotes molecular alignment, crystallization, and orientation. Genetic manipulation to extend ASG length significantly increased the Young's modulus and toughness of silkworm silk fibers. These findings demonstrate the potential of ASG length modulation as an effective strategy to improve silk fiber performance and provide valuable insights into the biological and functional importance of silk gland morphology.

Fish Collagen Peptides Preparation, Characteristics and Potential Applications

2025-06-23

Hari Eko Irianto , Giyatmi Gyatmi | CRC Press eBooks

Designed Fibril-Forming Mini-Collagens Engineered to Exhibit up to Two Orders of Magnitude Differences in Rates of Matrix Metalloproteinase I Susceptibility

2025-06-23

Jui Shivaji Chaugule , Yujia Xu | Biomacromolecules

The susceptibility to matrix metalloproteinases (MMPs) directly affects the functions and applications of collagen biomaterials. In this work, we demonstrated that this property can be manipulated in collagen-mimetic biomaterials created … The susceptibility to matrix metalloproteinases (MMPs) directly affects the functions and applications of collagen biomaterials. In this work, we demonstrated that this property can be manipulated in collagen-mimetic biomaterials created using designed peptides. We developed three fibril-forming mini-recombinant collagens (MRCs) using bacterial expression and designed genes that model a 108-residue section of human type III collagen surrounding the MMP-1 recognition site. Notably, the MRCs can form a native-like fibrillar structure representing the natural substrate of MMP-1. By altering the number of digestion sites or mutating the residues at the canonical scissile bond of MMP-1, the sensitivity to proteolysis of the MRCs varied by two orders of magnitude despite having homologous amino acid sequences and a similar fibrillar structure, and regardless of whether the peptides were in the triple helix conformation or as fibrils. These MRCs can be a versatile collagen alternative for regenerative medicine offering a regulated turnover rate catering to specific applications.

Heterogeneous molecular packing and water effects on the mechanical behaviour of silk-inspired β-sheet crystallites: A steered molecular dynamics study

2025-06-23

Cem Uguz , Ünsal Akdere , Çetin Taşseven | Computational Materials Science

Adsorption of Cr6+ and rhodamine 6G dye by modified silk fibroin: a comparative kinetic study

2025-06-23

R. Anbarasan , Nirmala Krishnan , Agathian Kandhan +1 more | Polymer Bulletin

Enhanced Bone Repair using Callus Organoids Derived from Urine‐Derived Stem Cells with Silk Fibroin

2025-06-23

Huifen Ding , Duanjing Chen , Xin Tan +5 more | Advanced Healthcare Materials

Abstract To address the increasing need of bone grafts for bone defect repair and the limitations of current strategies, this study introduces an innovative approach to bone reconstruction. Toward this … Abstract To address the increasing need of bone grafts for bone defect repair and the limitations of current strategies, this study introduces an innovative approach to bone reconstruction. Toward this end, a novel porous callus organoid that leverages self‐organized human urine‐derived stem cells (USCs), within a meticulously engineered cell‐aligned silk fibroin (SF) fiber network is developed to mimic the callus tissue formed during the osteogenesis of bone defects. This unique combination capitalizes on the exceptional mechanical properties and osteogenic potential of SF, along with the readily accessible and low‐risk nature of USCs. By precisely optimizing organoid's fiber density and fiber diameter, the system generates a porous and low oxidative stress microenvironment that not only sustains cell viability and activity, but also induces cell elongation and enhances cell–cell interactions, facilitating rapid callus organoid development within two weeks. When these USC fiber‐reinforced callus organoids are implanted into bone defects (5 mm in diameter), temporal advancement beyond the initial phase of natural bone healing is observed. This innovative system offers a cell‐sparing, cost‐effective therapeutic strategy that represents a significant advancement in bone reconstruction.

The Impact of PEO and PVP Additives on the Structure and Properties of Silk Fibroin Adsorption Layers

2025-06-21

Olga Yu. Milyaeva , Kseniya Yu. Rotanova , А. Р. Рафикова +3 more | Polymers

Materials formed with a base of silk fibroin (SF) are successfully used in tissue engineering since their properties are similar to those of natural extracellular matrixes. Mixing SF with different … Materials formed with a base of silk fibroin (SF) are successfully used in tissue engineering since their properties are similar to those of natural extracellular matrixes. Mixing SF with different polymers, for example, polyethylene oxide (PEO) and polyvinylpyrrolidone (PVP), allows the production of fibers, hydrogels, and films and their morphology to be controlled. The impact of PEO and PVP on formation and structure of SF adsorption layers was studied at different was studied at different polymer concentrations (from 0.002 to 0.5 mg/mL) and surface lifetimes. The protein concentration was fixed at 0.02 and 0.2 mg/mL. These concentrations are characterized by different types of spontaneously formed structures at the air–water interface. Since both synthetic polymers possess surface activity, they can penetrate the fibroin adsorption layer, leading to a decrease in the dynamic surface elasticity at almost constant surface tension and a decrease in ellipsometric angle Δ and adsorption layer thickness. As shown by AFM, the presence of polymers increases the porosity of the adsorption layer, due to the possible arrangement of protein and polymer molecules into separate domains, and can result in various morphology types such as fibers or tree-like ribbons. Therefore, polymers like PEO and PVP can be used to regulate the SF self-assembly at the interface, which in turn can affect the properties of the materials with high surface areas like electrospun matts and scaffolds.

Characterization of the Chaetae Autofluorescence in the Earthworm Eisenia foetida and their Role in Locomotion

2025-06-21

Melvin Rodríguez-Heredia , Martín Gerardo Rodríguez , Birmania Heredia Rivera +2 more | Journal of Fluorescence

The Rheb-mTORC1 Coordinates Cell Cycle Progression and Endoreplication in Bombyx mori

2025-06-20

Zhangchen Tang , Huawei Liu , Qingsong Liu +5 more | Insects

The mechanistic target of the Rapamycin complex 1 (mTORC1) signaling pathway plays a pivotal role in regulating crucial life processes, including cell growth and proliferation, by sensing and integrating various … The mechanistic target of the Rapamycin complex 1 (mTORC1) signaling pathway plays a pivotal role in regulating crucial life processes, including cell growth and proliferation, by sensing and integrating various signals, such as growth factors, energy status, and amino acids. Our previous studies showed that activation of the mTORC1 signaling pathway enhances silk protein synthesis and silk gland size. Here, the potential of the molecular mechanism mTORC1 to regulate the growth and development of silk gland cells was investigated. Inhibiting mTORC1 with rapamycin decreased proliferation in the Bombyx mori embryonic (BmE) cells and endoreplication in silk gland cells, reducing CyclinB and CyclinE protein levels and DNA content, and arresting the BmE cell cycle at G2/M. Conversely, the overexpression of Ras homolog enriched in brain (Rheb) led to increased proliferation of BmE cells and endoreplication in silk gland cells, as well as a significant elevation in DNA content. This study provides a molecular explanation for the increase in silk protein synthesis and silk gland length through the activation of mTORC1, thereby refining the regulatory network of the silkworm endoreplication and providing new molecular targets for breeding high-yield varieties of Bombyx mori.

Microfluidics Enabling the Controlled Manufacturing of Peptide and Protein Micro and Nano Biomaterials for Biomedical Applications

2025-06-19

Gaia Pascolo , Bekzod Bekchanov , Mohamed A. N. Soliman +6 more | Biomacromolecules

The intersection of microfluidics (MFs) and biomaterials has opened new avenues for the precise fabrication of micro- and nanostructures with tailored properties. Peptides and proteins are among these biomaterials recently … The intersection of microfluidics (MFs) and biomaterials has opened new avenues for the precise fabrication of micro- and nanostructures with tailored properties. Peptides and proteins are among these biomaterials recently gaining significant attention, offering unique advantages due to their biocompatibility, biodegradability, assembly into biofunctional structures, and potential for targeted interactions. This Review provides a comprehensive overview of advancements in manufacturing of peptide- and protein-based micro- and nanomaterials (PPMNs) using MFs and identifies gaps in current knowledge. We discussed key aspects of MFs systems relevant to the fabrication of micro- and nanostructures, including microchip design and material, as well as manufacturing parameters. By understanding these factors, researchers can optimize MFs systems to precisely tune the size, shape, and composition of the fabricated PPMNs, and get insights into future research directions and address current limitations. Digital approaches and standardization of MFs will accelerate translation of PPMNs for different biomedical applications.

Silkworm Enzyme Hydrolysates Improve Memory in MCI Models via CREB-BDNF Signaling and Enhanced Brain Mitochondrial Function

2025-06-19

Y.N. Kim , Phuong Nguyen , Nguyen Hoang +3 more | Nutrients

Background/Objectives: This study investigated whether enzymatic hydrolysis enhances the cognitive benefits of HongJam (steamed mature silkworms) and explored the underlying mechanisms. A marker compound of enzyme-treated HongJam was also identified … Background/Objectives: This study investigated whether enzymatic hydrolysis enhances the cognitive benefits of HongJam (steamed mature silkworms) and explored the underlying mechanisms. A marker compound of enzyme-treated HongJam was also identified to support quality control. Methods and Results: Mice were supplemented with Golden Silk HongJam (GS) or its enzyme hydrolysates (GS-EHS). Behavioral tests showed both improved fear-aggravated memory, with GS-EHS producing similar or greater effects at lower doses. GS-EHS activated the cyclic AMP response element binding protein/brain-derived neurotrophic factor signaling pathway and mitigated scopolamine-induced mitochondrial dysfunction by enhancing mitochondrial complex activity and ATP production. It also increased esterase activity, reduced reactive oxygen species, and modulated programmed cell death by suppressing apoptosis while promoting autophagy and unfolded protein response pathways. These changes led to reduced endoplasmic reticulum stress and neuroinflammation. Mass spectrometry identified glycine-tyrosine dipeptide as a potential bioactive marker. Conclusions: GS-EHS enhances cognitive function by improving mitochondrial activity, reducing oxidative stress, and regulating programmed cell death. Enzymatic hydrolysis appears to increase the bioavailability of active compounds, making GS-EHS effective at lower doses. The glycine–tyrosine dipeptide may serve as a marker compound for standardizing GS-EHS based on its cognitive-enhancing properties.

An innovative treatment for hypoxic-ischemic encephalopathy: Silk fibroin nanomaterials improve neural stem cell axon formation and facilitate cognitive improvement

2025-06-19

Chao Han , Shuna Chen , Zihan Shi +3 more | Neural Regeneration Research

Abstract Stem cell therapy shows promise for treating brain injuries; neural stem cells in particular are capable of repairing damage by forming new nerve cells and supporting recovery. However, optimizing … Abstract Stem cell therapy shows promise for treating brain injuries; neural stem cells in particular are capable of repairing damage by forming new nerve cells and supporting recovery. However, optimizing the implantation and functionality of these cells in damaged brain regions remains challenging. Silk fibroin, a natural protein derived from silkworm silk, is a biocompatible material with exceptional properties that are useful for tissue engineering. Its biodegradability, mechanical robustness, and ability to promote cell growth make it particularly valuable for biomedical applications. Silk fibroin nanomaterials, which comprise silk fibroin processed into nanostructures, offer enhanced surface area, improved loading capacity for bioactive molecules, and superior nanoscale interactions with cells compared with bulk silk fibroin materials. In this study, we first extracted human-derived neural stem cells from a 14-week-old human fetus. Then, neural stem cells were loaded with 1% silk fibroin nanomaterials, which was identified as the optimal concentration to support human-derived neural stem cell growth and release of neurotrophic factors. Finally, 1% silk fibroin nanomaterials were implanted into a rat model of hypoxic-ischemic brain injury. The results showed that, compared with the treatment with human-derived neural stem cells alone, silk fibroin hydrogel carrying human-derived neural stem cells was significantly more effective at alleviating brain tissue damage, increasing neurotrophic factor secretion in the brain microenvironment, and promoting motor and cognitive function recovery. These findings suggest that silk fibroin nanomaterials loaded with human-derived neural stem cells could be used to treat hypoxic-ischemic encephalopathy. However, the mechanisms and related signaling pathways by which hydrogels combined with cells exert their reparative effects still require further in-depth investigation.

The Identification of a New Gene KRTAP 6-3 in Capra hircus and Its Potential for the Diameter Improvement of Cashmere Fibers

2025-06-19

Jian Cao , Zhanzhao Chen , Jianmin Zhang +2 more | Genes

Cashmere is one of the important economic products of goats, and the KRTAP gene family, as an important family of regulatory genes in the growth process of cashmere fiber, largely … Cashmere is one of the important economic products of goats, and the KRTAP gene family, as an important family of regulatory genes in the growth process of cashmere fiber, largely affects the quality of cashmere. In this study, the KRTAP6-3 gene was identified and located on goat chromosome 1 using a goat genome homology search combined with a phylogenetic tree approach. The Longdong cashmere goat KRTAP6-3 gene variation and its effect on cashmere quality were explored by using the polymerase chain reaction single-stranded conformation polymorphism (PCR-SSCP) technique, in situ hybridization, and the allele presence/absence model. The results identified a total of six SNPs in KRTAP6-3, three of which were located in the coding region and two of which were synonymous mutations, in addition to 45- bp deletion sequences detected in alleles C and F. Moreover, the KRTAP6-3 mRNA showed a strong expression signal in the cortical layer of the primary and secondary follicles in the inner root sheaths, as well as in the cells of the hair papillae and the matrices during the anagen phase, and signaling at the sites described above is attenuated during the telogen phase. The presence of allele C was associated with increased MFD (mean fiber diameter) (p < 0.01). The MFD of goats with allele C genotype (genotype AC) was significantly higher (p < 0.05) than that of goats without allele C genotype (genotypes AA and AB). This indicates that genetic variation in the KRTAP6-3 gene in goats is significantly associated with cashmere traits and can serve as a candidate gene for molecular markers of cashmere traits.

Biosynthesis of a dual growth factors (GFs) functionalized silk sericin hydrogel to promote chronic wound healing in diabetic mice

2025-06-18

Hanxin Deng , Fangyu Wang , Yujuan Zhou +7 more | Bioactive Materials

Deciphering Biosurfactant-Salt Interaction and Its Influence on Biosurfactant Activity in Muga Silk Fibroin Extraction

2025-06-18

Bhagyashree Biswal , Manoja Das , Debadutta Das +2 more | Materials Chemistry and Physics

Synergistic Stabilization of Silkworm Pupal Protein and Xanthan Gum Pickering Emulsions for High-Precision 3D Food Printing

2025-06-18

Zinuo An , Liangbin Hu , Xiaoyue Gong +6 more | Food and Bioprocess Technology

Silk‐Fibroin as Biocompatible and Bioresorbable Enzyme Immobilization Matrix for Screen‐Printed Amperometric Glucose Biosensors

2025-06-18

Kevin A. Janus , Stefan Achtsnicht , Benedetta Isella +5 more | Advanced Sensor Research

Abstract Silk‐fibroin is utilized as a biocompatible and bioresorbable enzyme immobilization matrix and exemplarily demonstrated for a screen‐printed amperometric glucose biosensor. The silk‐fibroin is derived from the silkworm Bombyx mori … Abstract Silk‐fibroin is utilized as a biocompatible and bioresorbable enzyme immobilization matrix and exemplarily demonstrated for a screen‐printed amperometric glucose biosensor. The silk‐fibroin is derived from the silkworm Bombyx mori . The enzyme immobilization matrix consisting of silk‐fibroin, together with glucose oxidase from Aspergillus niger , is applied to a screen‐printed carbon‐based, biocompatible, and biodegradable working electrode on a flexible silk‐fibroin substrate. The biosensor is characterized electrochemically at physiological glucose concentrations in the range from 0.5 to 10 m m . The results are compared to a “conventional” glucose biosensor, also fabricated on a flexible silk‐fibroin substrate, however utilizing a laboratory standard enzyme immobilization matrix based on bovine serum albumin and glutaraldehyde. Furthermore, the influence of pH (pH 5.5 to pH 8.0) and temperature variations (21 to 70 °C) on these two different immobilization matrices are studied.

Immunomodulatory Potential and Biocompatibility of Chitosan–Hydroxyapatite Biocomposites for Tissue Engineering

2025-06-17

Davide Frumento , Ştefan Ţălu | Journal of Composites Science

Chitosan–hydroxyapatite (CS-HAp) biocomposites, combining the biocompatibility and bioactivity of chitosan with the osteoconductive properties of hydroxyapatite, are emerging as promising candidates for tissue engineering applications. These materials consistently exhibit excellent … Chitosan–hydroxyapatite (CS-HAp) biocomposites, combining the biocompatibility and bioactivity of chitosan with the osteoconductive properties of hydroxyapatite, are emerging as promising candidates for tissue engineering applications. These materials consistently exhibit excellent cytocompatibility, with cell viability rates greater than 95% in MTT and Neutral Red Uptake assays, and minimal cytotoxicity, as demonstrated by low levels of cell death in DAPI and Trypan blue staining. More importantly, CS-HAp biocomposites modulate the immune environment by enhancing the expression of anti-inflammatory cytokines (IL-10 and IL-4) and the pro-inflammatory cytokine TGF-β, while avoiding significant increases in TNF-α, IL-6, or NF-κB expression in fibroblast cells exposed to HAC and HACF scaffolds. In an in vivo dermatitis model, these biocomposites reduced mast cell counts and plasma histamine levels and significantly decreased pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), JAK1/3, VEGF, and AnxA1 levels. Structurally, HACF scaffolds demonstrated larger average pore sizes (95 µm) compared to HAC scaffolds (74 µm), with porosities of 77.37 ± 2.4% and 65.26 ± 3.1%, respectively. These materials exhibited high swelling ability, equilibrium water content, and controlled degradation over a week in culture media. In addition to their immunomodulatory effects, CS-HAp composites promote essential cellular activities, such as attachment, proliferation, and differentiation, thereby supporting tissue integration and healing. Despite these promising findings, significant gaps remain in understanding the underlying mechanisms of immune modulation by CS-HAp biocomposites, and formulation-dependent variability raises concerns about reproducibility and clinical application. Therefore, a comprehensive review is essential to consolidate existing data, identify key knowledge gaps, and standardize the design of CS/HAp composites for broader clinical use, particularly in immunomodulatory and regenerative medicine contexts.

Mechanism Exploration of Spider-Silk-Inspired Multiple-Hydrogen-Bond Polyurethane Healable Elastomers for Anticorrosion

2025-06-17

Haoran Xu , Shunli Wang , Wenlong Li +5 more | Nano Letters

Spider-silk-inspired multiple-hydrogen-bond polyurethane (PU) healable elastomers have garnered significant attention across various industries. While individual hydrogen bonds are relatively weak, their collective cooperation generates strong interaction forces with geometrically hydrogen-bond-confined … Spider-silk-inspired multiple-hydrogen-bond polyurethane (PU) healable elastomers have garnered significant attention across various industries. While individual hydrogen bonds are relatively weak, their collective cooperation generates strong interaction forces with geometrically hydrogen-bond-confined arrays. Under the guidance of this discovery, the synthesized PU elastomer (PU-MDI) had superior mechanical characteristics and a self-healing efficiency of 98%, which can provide a robust barrier to effectively delay the penetration of corrosive ions and resist external impact energy dissipation. PU-MDI exhibited excellent anticorrosion and anticavitation performance at conventional temperature. However, as temperature rose, the intensive multiple hydrogen bonds weakened and cracked, leading to a significant degradation in the functional properties of PU-MDI. This breakdown rendered PU-MDI unsuitable for elevated-temperature anticorrosion applications, and the study elucidated the inadequacy reasons. These findings offer critical insights into the practical application, directional development, and inadequacy prevention of multiple-hydrogen-bonded healable polymer materials, with implications for future anticorrosion and self-healing material innovation.

Nanohybrid Fibers via Direct Nanoparticle Injection into the Spider’s Silk Gland

2025-06-17

Anastasia Kryuchkova , Mariia Mikhailova , Pavel Zelenovskii +4 more | ACS Applied Bio Materials

Spider silk demonstrates an impressive balance of high strength and elasticity, which results from the hierarchical self-assembled structure of spider silk proteins during the fiber biosynthesis and spinning process. Enhancing … Spider silk demonstrates an impressive balance of high strength and elasticity, which results from the hierarchical self-assembled structure of spider silk proteins during the fiber biosynthesis and spinning process. Enhancing the mechanical characteristics of spider silk fibers and imparting them with functional properties has garnered considerable attention. This challenge underscores the importance of developing strategies for modifying native spider silk. In this study, we introduce an approach to modify the structure and properties of spider silk fibers by injecting magnetite hydrosols directly into the spiders' silk glands. This results not only in the magnetic functionality of spider silk fibers but also in 82% increase in Young's compared to native spider silk, along with hardness of 1.30 MPa. To explore the nature of this phenomenon, we analyzed the difference in the topography of native Holothele incei spider silk and Fe3O4-hybrid spider silk, as well as their corresponding mechanical behavior at the nanoscale. Additionally, we studied the changes in structure, composition, and morphology caused by the inclusion of magnetic nanoparticles. Our findings demonstrate that the polar and hydrophobic interactions between Fe3O4 nanoparticles and the amino acid residues in spider silk could influence Young's modulus and hardness of the Fe3O4/spider silk hybrid fibers by promoting the protein conformation from an amorphous phase to β-sheets. This can only be achieved when nanomaterials are integrated into the structure within the fiber. The developed approach enables the fabrication of modified spider silk fibers, which can aid in the fundamental study of native spider silk and the development of technologies to fully replicate the properties of native silk in the future. Furthermore, lightweight, flexible, but strong materials are critical in soft robotic applications, where these nanohybrid fibers not only ensure gentle manipulation and reliability, but also their magnetic properties allow for responsive movement and control.

Self-assembled green composites of silk fibroin and microfibrillated cellulose

2025-06-17

Melissa Puerta , Diego Gómez-Maldonado , Adriana Restrepo‐Osorio +1 more | MRS Bulletin

The Preparation of Silk Protein/Copper Sulfide Composite System and its Application in Tumor Treatment

2025-06-16

Wenli Li , Yuhua Han | International Journal of Biology and Life Sciences

Nanobiotechnology provides opportunities for targeted therapy of tumor drugs, and simple and effective methods for constructing nanotherapeutic agents has emerged as a research hotspot. Silk protein (SF) has biocompatibility, and … Nanobiotechnology provides opportunities for targeted therapy of tumor drugs, and simple and effective methods for constructing nanotherapeutic agents has emerged as a research hotspot. Silk protein (SF) has biocompatibility, and copper sulfide (CuS) has unique optical properties that have attracted the attention of researchers. This article mainly elaborates on the biological characteristics of silk protein and copper sulfide, studies the preparation method of SF/CuS nanocomposite system and its application in tumor treatment. It is found that there is relatively little research on this nanocomposite system, which will be a new direction for future research.

Gold nanoparticle/silk fibroin-based nanofiber enhances skin regeneration

2025-06-16

Ozan Özcan , Elif Tufan , Aleyna Muhan +3 more | Journal of Pharmacy and Pharmacology

Abstract Objectives The aim of this study was to determine the wound-healing potential of gold nanoparticles and silk fibroin-based nanofiber produced by green chemistry. Methods The electrospinning method was used … Abstract Objectives The aim of this study was to determine the wound-healing potential of gold nanoparticles and silk fibroin-based nanofiber produced by green chemistry. Methods The electrospinning method was used to prepare the nanofiber. Twenty rats were exposed to a 7-day treatment period and another 20 rats were exposed to a 21-day treatment period. Rat groups were control, silver, silk fibroin, and silk + gold nanoparticle groups for each period. The effect of the gold nanoparticle/silk fibroin-based nanofiber was examined in skin samples by using biochemical and histological analysis. In biochemical analysis, skin oxidant and antioxidant parameters were determined. Key findings Parameters indicating skin damage returned to their previous levels 7 and 21 days after the wound formation using gold nanoparticle/silk fibroin-based nanofiber. Gold nanoparticle/silk fibroin-based nanofiber initiated hair follicle formation at the wound site and accelerated the re-epithelialization process. Conclusions It was found that the nanofiber prepared by adding gold nanoparticles to silk fibroin had better wound-healing properties than silk fibroin nanofibers without gold nanoparticles.

Spider egg sacs reveal how pockets of air can be used to conserve water

2025-06-16

Katherine Karkosiak , R. Schwartz , Hunter King +1 more | Journal of Experimental Biology

Controlling water transport across surfaces is essential for all living organisms. Spider egg sacs are multifunctional membranes that protect eggs and spiderlings from the external environment. Past research gives conflicting … Controlling water transport across surfaces is essential for all living organisms. Spider egg sacs are multifunctional membranes that protect eggs and spiderlings from the external environment. Past research gives conflicting results about whether these mats of silk fibers reduce evaporation of water in part because the diffusive resistance of any membrane cannot be measured independently of the system in which it is studied. We develop a model to describe water vapor transport across porous surfaces that includes the important roles of the gap space underneath the membrane and the boundary layer on the outside of the membrane in controlling water vapor flux, in addition to the relative impermeability of the membrane itself. The model accurately predicts diffusive resistance of a variety of synthetic surfaces from empirical studies, as well as the egg sacs of the black widow Latrodectus hesperus and the garden spider Argiope aurantia. We show that “typical” spider egg sac membranes offer surprisingly low diffusive resistance to water because they are highly porous at microscopic scales. However, silk egg sacs still play key roles in controlling water loss by preserving and defining an internal region of stagnant air that often dominates the diffusive resistance of the whole system. Our model provides a tool to explore diverse spider egg sac geometries, but can also be adopted to fit a variety of systems to facilitate comparison and engineering of diffusive resistance across membranes.

Silk–Silk Composite Foams for Surgical Packing, Liquid Absorption, and Drug Delivery

2025-06-16

Benjamin J. Allardyce , Nigar Rashida , Dilendra Wijesekara +3 more | ACS Applied Materials & Interfaces

Degradable hemostatic materials such as gelatin foam are widely used as middle ear packing materials to support tympanic membrane grafts; while safe and biocompatible, such materials have limited mechanical stability … Degradable hemostatic materials such as gelatin foam are widely used as middle ear packing materials to support tympanic membrane grafts; while safe and biocompatible, such materials have limited mechanical stability when wet. Here, we demonstrate the fabrication of silk-silk composite foams by mixing microfibrillated silk with a low molecular weight silk solution glue to produce water-stable and highly porous foams that retain their structure when wet. The foams exhibited excellent (over 2000%) water absorption, more than 5 times higher than Gelfoam, a commercial hemostatic packing material, and hence higher loading of antibiotics such as ciprofloxacin. Moreover, unlike Gelfoam, ciprofloxacin could be encapsulated into the composite foams during fabrication to produce a dried, off-the-shelf, drug-eluting packing material. This enabled sustained drug release for over 16 days. The addition of microfibers significantly improved shape retention after annealing: samples containing at least a 1:1 mix of silk solution to microfibers showed no shrinkage after annealing, while control foams made from just silk solution shrank by at least 25%. These hybrid foams have immense potential for use as dual-function factor-concentrating hemostatic materials with drug delivery capacity for middle ear packing.

Correction: Expression of genes with biomarker potential identified in skin from DSLD-affected horses increases with age

2025-06-16

Jennifer Hope Roberts , Jian Zhang , Florent David +4 more | PLoS ONE

[This corrects the article DOI: 10.1371/journal.pone.0287740.]. [This corrects the article DOI: 10.1371/journal.pone.0287740.].

Condensate-driven chromatin organization via elastocapillary interactions

2025-06-15

Hongbo Zhao , Amy R. Strom , Jorine M. Eeftens +3 more | bioRxiv (Cold Spring Harbor Laboratory)

Biomolecular condensates are ubiquitous structures found throughout eukaryotic cells, with nuclear condensates playing a key role in the mesoscale organization and functionality of the genome. Protein- and RNA-rich liquid-like condensates … Biomolecular condensates are ubiquitous structures found throughout eukaryotic cells, with nuclear condensates playing a key role in the mesoscale organization and functionality of the genome. Protein- and RNA-rich liquid-like condensates form through phase separation on and around chromatin, driving diverse condensate morphologies with varying sphericity and intra-condensate chromatin density. However, a unifying set of physical principles underlying these varied interactions and their implications for chromatin organization remains elusive. Here, we develop and experimentally validate a mesoscopic model that bridges the physics of phase separation and chromatin mechanics. Specifically, by integrating computational modeling with experiments using two canonical condensate proteins, the heterochromatin protein HP1α, and the euchromatin protein BRD4, we demonstrate that wetting properties and chromatin stiffness shape condensate morphology, while condensates remodel chromatin mechanics and organization. This two-way interplay is governed by elastocapillarity (the deformation of chromatin by condensate interfacial tension) and resolves discrepancies in nuclear condensate behavior, with emergent behaviors that deviate from the simplest liquid-liquid phase separation (LLPS) models. Our findings underscore that nuclear condensates and chromatin cannot be studied in isolation, as they are fundamentally interdependent, impacted by biomolecularly-defined wetting properties, with implications for genome organization, transcriptional regulation, and epigenetic control in diverse phenotypes, including cancer. Beyond the nucleus, the methodologies we present offer a generalizable platform for exploring multiphase, multicomponent soft matter systems across a broad range of biological and synthetic contexts.

Rapid UV-induced and robust methacrylated silk fibroin reinforced polyacrylamide-based triple-crosslinked hydrogels

2025-06-14

Mili Tilieke , Xiong Shu , Lei Chen +6 more | International Journal of Biological Macromolecules

Teleost-specific ictacalcins exhibit similar structural organization, cation-dependent activation and transcriptional regulation as human S100 proteins

2025-06-14

Liz Hernández , Théo Paris , Maria Demou +7 more | bioRxiv (Cold Spring Harbor Laboratory)

S100 proteins are highly versatile calcium-binding proteins from vertebrates. Following extracellular release, they become instrumental in immune and antimicrobial defenses, initiating the inflammatory response through receptor signaling and providing direct … S100 proteins are highly versatile calcium-binding proteins from vertebrates. Following extracellular release, they become instrumental in immune and antimicrobial defenses, initiating the inflammatory response through receptor signaling and providing direct control of bacterial invaders via nutritional immunity. While mammalian S100s have been extensively studied, very little is known about the more recently discovered S100 proteins from teleost fish, including those with no strict orthologs in mammals. Comparable functioning between both clades would allow to expand their study into the highly popular zebrafish model, particularly suited for live imaging and mechanistic exploration of immune and inflammatory processes. To fill the gap of knowledge on teleost S100s, we here provide a detailed structural and biochemical characterization of S100i1 and S100i2 from Danio rerio, two teleost-specific S100s absent in mammals. We demonstrate that they nevertheless share conserved tertiary and quaternary organization with mammalian S100s. In addition, they exhibit comparable calcium binding properties and undergo a similar calcium-dependent activation mechanism. Furthermore, they display analogous expression pattern, being enriched in tissues highly exposed to the environment like gills and skin, the latter constituting an important reservoir of S100 proteins in mammals. Finally, our results show, for the very first time, that s100i2/i2 gene expression is differentially modulated in sterile disease conditions associated with sustained inflammation or high hypoxic state. Altogether, these findings underline the strong parallelism existing between mammalian and teleost-specific S100 proteins despite their divergent evolution, opening up new avenues to explore their biology in the zebrafish model.

The Cheap Silk Sericin Displaying Chaperone-Like Activity to Stabilize Protein and Facilitate Protein Refolding

2025-06-14

Junyu Zhang , Xingqing Xiao , Donghui Zhang +4 more | CCS Chemistry

Tuning of optical properties of multifunctional silk fibroin films patterned by silver nanoparticles

2025-06-14

C. S. Shivananda , Lakshmeesha Rao B , K. Swaroop | Next Materials

Effect of Tension Loading on the Degradation Mechanism of Silk for Ancient Thangka Conservation

2025-06-13

Haiyang Zhao , Hui Jing Lu , Siwen An +3 more | Fibers and Polymers

Biological Evaluation of Silver-Treated Silk Fibroin Scaffolds for Application as Antibacterial and Regenerative Wound Dressings

2025-06-13

Federica Paladini , Carmen Lanzillotti , Angelica Panico +1 more | Nanomaterials

Chronic wounds represent a major clinical challenge due to their prolonged healing process and susceptibility to bacterial colonization, particularly by biofilm-forming bacteria. To address these issues, in this work, silver-treated … Chronic wounds represent a major clinical challenge due to their prolonged healing process and susceptibility to bacterial colonization, particularly by biofilm-forming bacteria. To address these issues, in this work, silver-treated silk fibroin scaffolds were developed and tested as multifunctional wound dressings, combining antimicrobial and regenerative properties. Silk fibroin, a natural protein derived from Bombyx mori cocoons, is widely recognized for its biocompatibility and suitability for tissue engineering. In this study, porous silk fibroin scaffolds were functionalized with silver nanoparticles through a photo-reduction process and were comprehensively tested for their cytocompatibility and wound healing potential. The excellent antibacterial activity of the silver-treated scaffolds was demonstrated against Escherichia coli and antibiotic-resistant Pseudomonas aeruginosa, as was extensively reported in a previous work. Biological assays were performed using 3T3 fibroblasts cultured on both untreated and silver-treated silk fibroin scaffolds. Biocompatibility assays, such as MTT, Live/Dead, and cytoskeleton analyses, demonstrated biocompatibility in both scaffold types, comparable to the control. Wound healing potential was assessed using in vitro scratch assays, revealing full wound closure (100%) after 24 h in cells cultured with untreated and silver-treated silk fibroin scaffolds, in contrast to 78.5% closure in the control. Notably, silver-treated scaffolds exhibited enhanced fibroblast repopulation within the wound gap, suggesting a synergistic effect of silver and fibroin in promoting tissue regeneration. These findings demonstrate that silver-treated silk fibroin scaffolds possess both anti-microbial and regenerative properties, making them promising candidates for chronic wound management applications.

Development and Analysis of an Antimicrobial <scp>PMMA</scp> Denture Base Infused With a Range of Silk Fibroin, Cannabinoids, and Hemp Fiber

2025-06-13

Süha Kuşçu , Yeliz Hayran , Ali Aydın | Journal of Applied Polymer Science

ABSTRACT An innovative approach to enhance the usability of poly(methyl methacrylate) (PMMA) might include incorporating silk fibroin (SF), hemp fiber (HF), and cannabinoids. This study aims to evaluate how the … ABSTRACT An innovative approach to enhance the usability of poly(methyl methacrylate) (PMMA) might include incorporating silk fibroin (SF), hemp fiber (HF), and cannabinoids. This study aims to evaluate how the addition of cannabinoids, SF, and HF affects the antimicrobial properties of PMMA. Cannabinoid fractions were obtained using supercritical CO 2 extraction, molecular distillation, and flash chromatography. Silk cocoons were cleaned, sericin removed, and washed with deionized water. Fibroin fiber underwent dissolution through the Ajisawa method, followed by dialysis in a urea solution before being lyophilized. Hemp fibers were dried, separated, and prepared in pure form. Determining the structural and physical properties of a novel PMMA is crucial for understanding its potential applications. Therefore, XRD and FT‐IR analyses characterized cannabinoid‐infused PMMA products synthesized with SF and HF. The biological characteristics of the newly improved PMMA products were evaluated through MTT, LDH, and SEM analyses, which are essential for assessing biocompatibility, cytotoxicity, and surface morphology, thereby providing comprehensive insight into their suitability for biomedical applications. HF and SF displayed mild antimicrobial qualities that reinforced the effectiveness of PMMA denture bases. Moreover, incorporating cannabinoid fractions into PMMA significantly enhances its antimicrobial properties, inhibiting oral pathogen growth. Additionally, hemp fiber, silk fibroin, and cannabinoid fractions are compatible with the denture base material, preserving its biological properties. This approach presents a cost‐effective strategy for improving PMMA's antimicrobial properties, with potential applications in enhancing oral health.

Silk Fibroin-Based Wound Dressings: Advances Toward Smart Trauma Care Platforms

2025-06-12

Zhang Dang , Han Zhang , Qinxin Liu +4 more | Sensors and Actuators A Physical

Correction: Proteomic analysis of silk fibroin reveals diverse biological function of different degumming processing from different origin

2025-06-12

Yaling Wang , Yunyun Liang , Jiacen Huang +6 more | Frontiers in Bioengineering and Biotechnology