Preparation of Regenerated Silk Fibroin Hybrid Fibers with Hydrogen Peroxide Sensing Properties by Wet Spinning

Silk is widely used in the production of high-quality textiles.At the same time,the amount of silk textiles no longer in use and discarded is increasing,resulting in significant waste and pollution.This issue is of great concern in many countries where silk is used.Hydrogen peroxide as a naturally occurring compound is an important indicator of detection in both biology and the environment.This study aims to develop a composite fiber with hydrogen peroxide-sensing properties using discarded silk materials.To achieve this goal,firstly,polydopamine(PDA)was used to encapsulate the ZnFe_(2)O_(4) NPs to achieve the improvement of dispersion,and then regenerated silk fibroin(RSF)and PDA@ZnFe_(2)O_(4)/RSF hybrid fibers are prepared by wet spinning.Research has shown that PDA@ZnFe_(2)O_(4)/RSF demonstrates exceptional sensitivity,selectivity,and stability in detecting hydrogen peroxide,while maintaining high mechanical strength.Furthermore,the complete hybridization of PDA@ZnFe_(2)O_(4) with silk fibroin not only results in the combination of the durability of silk fibroin and PDA@ZnFe_(2)O_(4)’s rigidity,ensuring a reliable service life,but also makes PDA@ZnFe_(2)O_(4)/RSF exhibit excellent catalytic activity and biocompatibility.Therefore,the composite fiber exhibits exceptional mechanical properties and reliable hydrogen peroxide sensing capabilities,making it a promising material for biological and medical applications.

Effects of Nano-patterning Modification on the Cell Proliferation and Adhesion in Burn Wound Healing of Regenerated Silk Fibroin Membrane

Objective:To investigate the effect of nano-patterning modification on the cell proliferation and adhesion in burn wound healing of regenerated silk fibroin membrane.Methods:A total of 60 healthy SD mice were randomly divided into three groups:group A received treatment involving nano-patterning on the surface of regenerated silk fibroin membrane,group B received treatment with recombinant human epidermal growth factor gel,and group C received the same treatment with recombinant human epidermal growth factor gel,with 20 cases in each group.Wound healing,surface structure,protein adsorption,cell proliferation and adhesion were assessed at intervals of 5th,15th and 25th d after treatment.Results:The findings indicated that:(1)The duration and pace of wound healing in groups A and B surpassed those of group C,with group A exhibiting superior results compared to group B(P<0.05);(2)Histopathological analysis revealed a progressive increase in neovascularization and fibroblast count in wound tissue across the 5th,15th,and 25th days for all three groups,with group C exhibiting a higher count of neovascularization and fibroblasts in unhealed tissue compared to groups A and B.(3)The levels of basic calponin expression in group A and group B showed an increase on the 5th and 15th day,followed by stabilization on the 25th day.In group C,the expression of basic calponin was initially high on the 5th day,and then stabilized on the 15th and 25th day(P<0.05);(4)The expression of fibroblast proliferating cell nuclear antigen in the wound tissue of mice in all three groups peaked on the 15th day and subsequently declined.The expression of PCNA in group A and group B was higher than that in group C at each time point,with group A exhibiting higher levels than group B(P<0.05);(5)As wounds healed,there was a reduction in apoptotic cells within the wound tissues of mice across three groups,with group a exhibiting a lower count compared to groups B and C(P<0.05).Conclusion:Nanopatterning on the surface of regenerated silk fibroin membrane can enhance the biocompatibility of burn wound treatment and promote the proliferation and adhesion of reparative cells.

Cytocompatibility of regenerated silk fibroin film:a medical biomaterial applicable to wound healing

Objective： To explore the feasibility of using regenerated silk fibroin membrane to construct artificial skin substitutes for wound healing, it is necessary to evaluate its cytocompatibility. Methods： The effects of regenerated silk fibroin film on cytotoxicity, adhesion, cell cycle, and apoptosis of L929 cells, growth and vascular endothelial growth factor （VEGF） expression of ECV304 cells, and VEGF, angiopoietin-1 （Ang-1）, platelet-derived growth factor （PDGF） and fibroblast growth factor 2 （FGF2） expression of WI-38 cells were assessed by 3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-di-phenytetrazoliumromide （MTT） assay, viable cell counting, flow cytometry （FCM）, and enzyme-linked immunosorbant assay （ELISA）. Results： We showed that the regenerated silk fibroin film was not cytotoxic to L929 cells and had no adverse influence on their adhesion, cell cycle or apoptosis; it had no adverse influence on the growth and VEGF secretion of ECV304 cells and no effect on the secretion of VEGF, Ang-1, PDGF and FGF2 by WI-38 cells. Conclusion： The regenerated silk fibroin film should be an excellent biomaterial with good cytocompatibility, providing a framework for reparation after trauma in clinical applications.

Methylene green-mediated sensor highly sensitive to hydrogen peroxide based on entrapment of horseradish peroxidase in composite membrane of regenerated silk fibroin and poly(vinyl alcohol)

A novel composite membrane of poly(vinyl alcohol) and regenerated silk fibroin was employed to immobilize horseradish peroxidase (HRP) and IR was used to give a useful insight into the structure of the composite membrane before and after ethanol treatment. A methylene green-mediated sensor sensitive to hydrogen peroxide was fabricated, based on the composite membrane as immobilization matrix for HRP. Cyclic voltammetry and amperometric measurement were for the first time utilized to demonstrate the suitability of methylene green as an electron transfer mediator between immobilized HRP and a glassy carbon electrode in bioelectrocatalytic reduction of hydrogen peroxide. Performance and characteristics of the sensor were evaluated in respect to response time, detection limit, applied potential and concentration of the mediator. The sensor possesses a variety of characteristics including good sensitivity, rapid response time and low detection of limit of 0.1 mu mol/L.

Fabrication of High Toughness Silk Fibroin/Tungsten Disulfide Nanoparticles Hybrid Fiber and Self-Heating Textile by Wet Spinning|

Traditionally,silkworm silk has been used to make high-quality textiles.Nevertheless,various wastes from silk-worm silk textiles that are no longer used are increasing.which is also causing considerable waste and contam-ination.This issue is causing widespread concern in countries that use more silk.Regenerated silk fibroin(RSF)fibers have been shown to be fragile and tender,which prohibits RSF from being widely used as a structural com-ponent.Therefore,enriching the function of silk and enhancing the RSF mechanial properties are important directions to expand the comprehensive utilization of silk products.In the present research,wet spinning was used to create a series of RSF/tungsten disulfide(WS_(2))nanoparticles(NPs)hybrid fiber having distinct WS_(2) nanoparticles concentrations.It was discovered that the temperature of hybrid fibers containing 0.8 wt%RSF/WS_(2) nanoparticles might climb from 20.4℃ to 85.6℃in 1 min and 108.3℃ in 10 min after being exposed to simulated sunlight for a period of one minute and ten minutes.It also had certain antibacterial activity and thermal stability.Fabrics created by hand mixing had outst anding photothermal characteristics under natural sunlight.Further-more,adding WS_(2) nanoparticles might increase the tensile properties of hybrid fibers,which could be caused by the reality that the blending of WS_(2) nanoparticles inhibited the self-assembly of sheets in RSF reaction mixture in a dosage dependent way,as evidenced by the fact that RSF/WSz nanoparticles hybrid fibers had lesser β-sheets material,crystalline nature,and arystalline size.The above performance makes the RSF/WS_(2) nanoparticles hybrid fbers promising candidates for application in photothermal fabrics as well as military dothing.

Electrospun and woven silk fibroin/poly(lactic-coglycolic acid) nerve guidance conduits for repairing peripheral nerve injury

We have designed a novel nerve guidance conduit（NGC） made from silk fibroin and poly（lactic-co-glycolic acid） through electrospinning and weaving（ESP-NGCs）. Several physical and biological properties of the ESP-NGCs were assessed in order to evaluate their biocompatibility. The physical properties, including thickness, tensile stiffness, infrared spectroscopy, porosity, and water absorption were determined in vitro. To assess the biological properties, Schwann cells were cultured in ESP-NGC extracts and were assessed by morphological observation, the MTT assay, and immunohistochemistry. In addition, ESP-NGCs were subcutaneously implanted in the backs of rabbits to evaluate their biocompatibility in vivo. The results showed that ESP-NGCs have high porosity, strong hydrophilicity, and strong tensile stiffness. Schwann cells cultured in the ESP-NGC extract fluids showed no significant differences compared to control cells in their morphology or viability. Histological evaluation of the ESP-NGCs implanted in vivo indicated a mild inflammatory reaction and high biocompatibility. Together, these data suggest that these novel ESP-NGCs are biocompatible, and may thus provide a reliable scaffold for peripheral nerve repair in clinical application.

Piezoresistive MXene/Silk fibroin nanocomposite hydrogel for accelerating bone regeneration by Re-establishing electrical microenvironment

The electrical microenvironment plays an important role in bone repair.However,the underlying mechanism by which electrical stimulation(ES)promotes bone regeneration remains unclear,limiting the design of bone microenvironment-specific electroactive materials.Herein,by simple co-incubation in aqueous suspensions at physiological temperatures,biocompatible regenerated silk fibroin(RSF)is found to assemble into nanofibrils with aβ-sheet structure on MXene nanosheets,which has been reported to inhibit the restacking and oxidation of MXene.An electroactive hydrogel based on RSF and bioencapsulated MXene is thus prepared to promote efficient bone regeneration.This MXene/RSF hydrogel also acts as a piezoresistive pressure transducer,which can potentially be utilized to monitor the electrophysiological microenvironment.RNA sequencing is performed to explore the underlying mechanisms,which can activate Ca^(2+)/CALM signaling in favor of the direct osteogenesis process.ES is found to facilitate indirect osteogenesis by promoting the polarization of M2 macrophages,as well as stimulating the neogenesis and migration of endotheliocytes.Consistent improvements in bone regeneration and angiogenesis are observed with MXene/RSF hydrogels under ES in vivo.Collectively,the MXene/RSF hydrogel provides a distinctive and promising strategy for promoting direct osteogenesis,regulating immune microenvironment and neovascularization under ES,leading to re-establish electrical microenvironment for bone regeneration.

A nonmulberry silk fibroin-based robust mandruka for rapid hemostasis treatment

Uncontrolled hemorrhage resulting from traumas causes severe health risks.There is an urgent need for expeditious hemostatic materials to treat bleeding incidents.Here,we developed a natural protein-based hemostatic sponge extracted from nonmulberry cocoons that exhibited rapid coagulation and effective absorption.We first built a degumming and dissolution system suitable for the Dictyoploca japonica cocoons to obtain regenerated silk fibroin(DSF).The DSF was then combined with carboxymethyl chitosan(CMCS)by glutaraldehyde(GA)crosslinking to ensure the structural stability of sponges.The resulting DSF–CMCS–GA exhibited remarkable hemostatic properties,displaying the highest absorption rate.It also demonstrated comparable efficacy to commercial hemostatic sponges.The blood-clotting index and hemolysis test showed that the prepared sponge possessed hemostatic activity and good hemocompatibility.Compared with mulberry silk fibroin hemostatic sponges(SF–CMCS–GA),DSF–CMCS–GA showed slightly better effects,making them a potential alternative to mulberry silk.In conclusion,our study introduces the use of Dictyoploca japonica silk fibroin for hemostasis,highlighting the exploitation of wild silkworm resources and providing an excellent silk fibroin-based hemostatic sealant for acute accident wounds and biomedical applications involving massive hemorrhage.