Electrospun Silk Fibroin Research Articles

Piezoelectric silk fibroin nanofibers: Structural optimization to enhance piezoelectricity and biostability for neural tissue engineering

Silk fibroin (SF) has garnered significant interest in tissue engineering due to its excellent biocompatibility and bioactivity. Notably, SF exhibits piezoelectric properties that can be harnessed to electrically stimulate cells, enhancing tissue morphogenesis. However, a systematic approach to control SF's piezoelectricity and biodegradation, and its application in neural morphogenesis, has not been fully explored. In this study, SF was electrospun into nanofibers of various sizes and subjected to a post-electrospinning chemical treatment to examine the effects of phase composition, especially the β-sheet formation, on the piezoelectricity and biostability of SF. The optimized SF scaffolds having a nanofiber diameter of 750 nm and a scaffold thickness of 250 µm allowed for the maintenance of nanofibrous structure for at least 6 weeks in aqueous environments while maintaining piezoelectric potential outputs of at least 200 mVp-p. This enabled cell membrane depolarization over an extended cell culture duration, facilitating the functional maturation of human neural stem cells (hNSCs). Specifically, acoustic piezo-activation of the SF scaffolds, resulting in mechano-electrical stimulation (MES) of the cells, accelerated their differentiation into neurons, astrocytes, and especially oligodendrocytes, leading to robust axon myelination within two weeks. Furthermore, MES enhanced neural connectivity and functional maturity, as evidenced by significant increases in excitatory and inhibitory synapse formation (46 % and 58 %, respectively), action potential amplitude (252 %), and velocity (210 %) compared to static control conditions. These findings demonstrate the potential of biodegradable electrospun SF nanofibers with balanced piezoelectricity and biostability for advancing neural tissue engineering.

A facile nanopattern modification of silk fibroin electrospun scaffold and corresponding impact on cell proliferation and osteogenesis

Abstract As a well-known natural protein biomaterial, silk fibroin (SF) has shown broad application prospects in typical biomedical fields. However, the mostly used SF from Bombyx mori silkworm lacks specific cell adhesion sites and other bioactive peptide sequences, and there is still significant room for further improvement of their biological functions. Therefore, it is crucial to develop a facile and effective modification strategy for this widely researched biomaterial. In this study, the SF electrospun scaffold has been chosen as a typical SF biomaterial, and air plasma etching has been adopted as a facile nanopattern modification strategy to promote its biological functions. Results demonstrated that the plasma etching could feasibly and effectively create nano-island-like patterns on the complex surface of SF scaffolds, and the detailed nanopattern features could be easily regulated by adjusting the etching time. In addition, the mesenchymal stem cell responses have illustrated that the nanopattern modification could significantly regulate corresponding cell behaviors. Compared with the non-etched scaffold, the 10 min-etched scaffold (10E scaffold) significantly promoted stem cell proliferation and osteogenic differentiation. Moreover, 10E scaffold has also been confirmed to effectively accelerate vascularization and ectopic osteogenesis in vivo using a rat subcutaneous implantation model. However, the mentioned promoting effects would be weakened or even counteracted with the increase of etching time. In conclusion, this facile modification strategy demonstrated great application potential for promoting cell proliferation and differentiation. Thus, it provided useful guidance to develop excellent SF-based scaffolds suitable for bone and other tissue engineering.

Silk Fibroin Nanofibers: Advancements in Bioactive Dressings through Electrospinning Technology for Diabetic Wound Healing

Background: Non-healing diabetic wounds represent a significant clinical challenge globally, necessitating innovative approaches in drug delivery to enhance wound healing. Understanding the pathogenesis of these wounds is crucial for developing effective treatments. Bioactive dressings and polymeric nanofibers have emerged as promising modalities, with silk biomaterials gaining attention for their unique properties in diabetic wound healing. Purpose of Review: The purpose of this review is to examine the challenges and innovations in treating non-healing diabetic wounds, emphasizing the global burden and the need for effective solutions. This review explores the complex mechanisms of wound healing in diabetes and evaluates the therapeutic potential of bioactive dressings and polymeric nanofibers. Special focus is given to the application of silk biomaterials, particularly silk fibroin, for wound healing, detailing their properties, mechanisms, and clinical translation. This review also describes various nanofiber fabrication methods, especially electrospinning technology, and presents existing evidence on the effectiveness of electrospun silk fibroin formulations. Recent Findings: Recent advancements highlight the potential of silk biomaterials in diabetic wound healing, owing to their biocompatibility, mechanical strength, and controlled drug release properties. Electrospun silk fibroin-based formulations have shown promising results in preclinical and clinical studies, demonstrating accelerated wound closure and tissue regeneration. Summary: Non-healing diabetic wounds present a significant healthcare burden globally, necessitating innovative therapeutic strategies. Bioactive dressings and polymeric nanofibers, particularly silk-based formulations fabricated through electrospinning, offer promising avenues for enhancing diabetic wound healing. Further research is warranted to optimize formulation parameters and validate efficacy in larger clinical trials.

Tuning Recombinant Perlecan Domain V to Regulate Angiogenic Growth Factors and Enhance Endothelialization of Electrospun Silk Vascular Grafts.

Synthetic vascular grafts are used to bypass significant arterial blockage when native blood vessels are unsuitable, yet their propensity to fail due to poor blood compatibility and progressive graft stenosis remains an intractable challenge. Perlecan is the major heparan sulfate (HS) proteoglycan in the blood vessel wall with an inherent ability to regulate vascular cell activities associated with these major graft failure modes. Here the ability of the engineered form of perlecan domain V (rDV) to bind angiogenic growth factors is tuned and endothelial cell proliferation via the composition of its glycosaminoglycan (GAG) chain is supported. It is shown that the HS on rDV supports angiogenic growth factor signaling, including fibroblast growth factor (FGF) 2 and vascular endothelial growth factor (VEGF)165, while both HS and chondroitin sulfate on rDV are involved in VEGF189 signaling. It is also shown that physisorption of rDV on emerging electrospun silk fibroin vascular grafts promotes endothelialization and patency in a murine arterial interposition model, compared to the silk grafts alone. Together, this study demonstrates the potential of rDV as a tunable, angiogenic biomaterial coating that both potentiates growth factors and regulates endothelial cells.

Electrospun Silk Fibroin and Collagen Composite Nanofiber Incorporated with Palladium and Platinum Nanoparticles for Wound Dressing Applications

Electrospun Silk Fibroin and Collagen Composite Nanofiber Incorporated with Palladium and Platinum Nanoparticles for Wound Dressing Applications

Physicochemical Properties of Silk Fibroin Electrospun Membranes Functionalized with Gold Nanoparticles and Choline Based Bio-Ionic Liquids

Tissue engineering has focused on the development of biomaterials, modulating the morphological and electrochemical characteristics based on their final application. In this setting, the purpose of the present study was to determine the physicochemical response of electrospun membranes of silk fibroin extracted from sericulture wastes and their functionalization with choline based bio-ionic liquids. A comparative study of their response was carried out with membranes obtained from the same protein but functionalized with gold nanoparticles. The biomaterials developed were characterized by UV-Visible spectrophotometry, FTIR spectroscopy, electron microscopy (SEM and FESEM), dynamic light scattering (DLS), and Linear sweep voltammetry. The results obtained showed a fibrillar morphology and the conduction of electrical stimuli by the membranes functionalized with the gold nanoparticles or the bio-ionic liquids, where for the latter the response is modulated by the concentration used in the development of the biocomposite.

Next-generation self-adhesive dressings: Highly stretchable, antibacterial, and UV-shielding properties enabled by tannic acid-coated cellulose nanocrystals

Hydrogels with excellent high-water uptake and flexibility have great potential for wound dressing. However, pure hydrogels without fiber skeleton faced poor water retention, weak fatigue resistance, and mechanical strength to hinder the development of the dressing as next-generation functional dressings. We prepared an ultrafast gelation (6 s) Fe3+/TA-CNC hydrogel (CTFG hydrogel) based on a self-catalytic system and bilayer self-assembled composites. The CTFG hydrogel has excellent flexibility (800% of strain), fatigue resistance (support 60% compression cycles), antibacterial, and self-adhesive properties (no residue or allergy after peeling off the skin). CTFG@S bilayer composites were formed after electrospun silk fibroin (SF) membranes were prepared and adhesive with CTFG hydrogels. The CTFG@S bilayer composites had significant UV-shielding (99.95%), tensile strain (210.9 KPa), and sensitive humidity-sensing properties. Moreover, the integrated structure improved the mechanical properties of electrospun SF membranes. This study would provide a promising strategy for rapidly preparing multifunctional hydrogels for wound dressing.

Electrospun fibers based anisotropic silk fibroin film with photodynamic antibacterial therapy for S. aureus infected wound healing

Bacterial infection has been regarded as a life-threatening problem in clinic. In addition to screening of new antibiotics, it is important to develop highly effective antibacterial materials against antibiotic resistance with capacities on modulating chronic inflammation. Herein, aligned Chlorin e6 (Ce6) conjugated silk fibroin electrospun fibers were successfully fabricated on silk fibroin based film via electrospining to achieve effective photodynamic antibacterial activities under near infrared (NIR) irradiation. The aligned electrospun fiber based film composite (SFCF@Film) exhibited good mechanical properties and desirable hemocompatibility. SFCF@Film provided a promising guidance cue for directing cell orientation and promoting cell growth. Significantly, SFCF@Film effectively generated ROS under NIR irradiation to kill S. aureus for treating wound infections within 10 min and promoted M2 polarization of macrophages for wound healing at later stage. Therefore, we believed that this engineered bioscaffold can be a powerful strategy for handling wound infection.

Optimization and evaluation of oxygen-plasma-modified, aligned, poly (Є-caprolactone) and silk fibroin nanofibrous scaffold for corneal stromal regeneration

The shortage of human donor corneas for transplantation necessitates the exploration of tissue engineering approaches to develop corneal substitutes. However, these substitutes must possess the necessary strength, transparency, and ability to regulate cell behaviour before they can be used in patients. In this study, we investigated the effectiveness of an oxygen plasma surface-modified poly-ε-caprolactone (PCL) combined with silk fibroin (SF) nanofibrous scaffold for corneal stromal regeneration. To fabricate the electrospun scaffolds, PCL and SF blends were used on a rotating mandrel. The optimization of the blend aimed to replicate the structural and functional properties of the human cornea, focusing on nanofibre alignment, mechanical characteristics, and in vitro cytocompatibility with human corneal stromal keratocytes. Surface modification of the scaffold resulted in improved transparency and enhanced cell interaction. Based on the evaluation, a composite nanofibrous scaffold with a 1:1 blend of PCL and SF was selected for a more comprehensive analysis. The biological response of keratocytes to the scaffold was assessed through cellular adhesion, proliferation, cytoskeletal organization, gene expression, and immunocytochemical staining. The scaffold facilitated the adhesion of corneal stromal cells, supporting cell proliferation, maintaining normal cytoskeletal organization, and promoting increased expression of genes associated with healthy corneal stromal keratocytes. These findings highlight the potential of a surface-modified PCL/SF blend (1:1) as a promising scaffolding material for corneal stromal regeneration. The developed scaffold not only demonstrated favourable biological interactions with corneal stromal cells but also exhibited characteristics aligned with the requirements for successful corneal tissue engineering. Further research and refinement of these constructs could lead to significant advancements in addressing the shortage of corneas for transplantation, ultimately improving the treatment outcomes for patients in need.

Biodegradable radiative cooling membrane based on electrospun silk fibroin fiber

AbstractBiodegradable radiative cooling materials can achieve both zero‐energy cooling and environmental friendliness. Natural silk cocoon exhibits both high solar reflectivity and mid‐infrared emissivity owing to its unique structure and composition, while it possesses excellent biodegradability. Herein, we restructure the natural silk by electrospinning to obtain scalable and biodegradable silk fibroin (SF) fiber membranes with enhanced optical properties. Specially, nano‐sized fibers exhibit better optical properties than micrometer‐sized ones. The fabricated SF nanofiber membrane can achieve ultra‐high average solar reflectance and infrared emittance of 96% and ~97%, respectively. Such outstanding optical properties enables the fiber membrane to yield an average sub‐ambient cooling temperature of ~6°C in the outdoor environment even under a peak solar intensity of ~800 W m−2. Overall, the resulted SF fiber membranes promise a wide range of applications such as building energy efficiency, cold‐chain transportation, in‐vehicle temperature control, outdoor precision instrument protection and outdoor personal thermal management.

Detection of Limbal Stem Cells Adhered to Melt Electrospun Silk Fibroin and Gelatin-Modified Polylactic Acid Scaffolds.

Limbal stem cells (LSCs) are of paramount importance in corneal epithelial tissue repair. The cornea becomes opaque in case of limbal stem cell deficiency (LSCD), which may cause serious damage to the ocular visual function. There are many techniques to restore damaged epithelium, one of which is the transplantation of healthy cultured LSCs, usually onto a human amniotic membrane or onto bio-based engineered scaffolds in recent years. In this study, melt electrospun polylactic acid (PLA) was modified by silk fibroin or gelatin and further cultured with LSCs originating from three different donors. In terms of physicochemical properties, both modifications slightly increased PLA scaffold porosity (with a significantly larger pore area for the PLA/gelatin) and improved the scaffolds' swelling percentage, as well as their biodegradation rate. In terms of the scaffold application function, the aim was to detect/visualize whether LSCs adhered to the scaffolds and to further determine cell viability (total number), as well as to observe p63 and CK3 expressions in the LSCs. LSCs were attached to the surface of microfibers, showing flattened conformations or 3D spheres in the formation of colonies or agglomerations, respectively. All scaffolds showed the ability to bind the cells onto the surface of individual microfibers (PLA and PLA/gelatin), or in between the microfibers (PLA/silk fibroin), with the latter showing the most intense red fluorescence of the stained cells. All scaffolds proved to be biocompatible, while the PLA/silk fibroin scaffolds showed the highest 98% viability of 2.9 × 106 LSCs, with more than 98% of p63 and less than 20% of CK3 expressions in the LSCs, thus confirming the support of their growth, proliferation and corneal epithelial differentiation. The results show the potential of these bio-engineered scaffolds to be used as an alternative clinical approach.

A Novel Composite Nano-scaffold with Potential Usage as Skin Dermo-epidermal Grafts for Chronic Wound Treatment

Background: Nano-scaffolds loaded with bioactive compounds such as ZnO nanoparticles (ZnO-NPs), as tissue-engineered artificial skin grafts, can be a suitable substitute for extracellular matrix and greatly contribute to accelerating chronic wound treatment by decreasing the chance of bacterial infection. Methods: Silk fibroin nanofiber was fabricated by using electrospinning and three-dimensional porous hybrids (3DPH) nano-scaffold with composite of sodium alginate/ZnO-NPs solution and silk fibroin electrospun nanofibers by adopting freeze-drying method. Successful configuration of nanofibers and porous nano-scaffolds were confirmed using field emission scanning electron microscopy (FE-SEM). Antimicrobial activity, cell attachment, and cytotoxicity evaluation of scaffolds were performed by employing disk diffusion method, L929 cell culture, and MTT assay, respectively. Results: Antibacterial analysis of 3DPH nano-scaffolds revealed their appropriate antibacterial activity against the Staphylococcus aureus and the Escherichia coli bacteria. Furthermore, the results from cytotoxicity and cell adhesion analyses indicated the appropriate cell attachment, viability, and proliferation on the silk fibroin nanofibers and 3DPH nano-scaffold, which are fundamental for wound healing and skin dermo-epidermal grafts. Conclusions: In sum, silk fibroin nanofiber as an epidermal graft and 3DPH nano-scaffold loaded with ZnO-NPs as a dermal graft were fabricated. Moreover, 1.5% (w/v) concentrations of ZnO-NPs were selected and incorporated into the 3DPH nano-scaffold. Considering the promising results of biological analyses, the nanofibrous and 3DPH nano-scaffolds composite may have been suitable for skin dermo-epidermal grafts and skin regeneration.

Engineered periosteum-diaphysis substitutes with biomimetic structure and composition promote the repair of large segmental bone defects

The repair of large segmental bone defects remains a big challenge due to limited self-healing capacity of bone. Digging into the structure and composition of natural long bone let us realize that the periosteum cambium on the surface of diaphysis plays a crucial role in bone repair. In this study, we explored the feasibility of using a tissue-engineered periosteum-diaphysis substitute to repair the large segmental bone defects. To create an artificial periosteum cambium, bone marrow mesenchymal stem cells (BMSCs) and endothelial progenitor cells (EPCs) were co-cultured on electrospun silk fibroin (SF) fibrous membranes for mimicking the cellular composition and microstructure of cambium layer of the native periosteum. These SF membranes supported the adhesion and proliferation of both BMSCs and EPCs. In addition, we found that a 1:1 ratio of BMSCs and EPCs supported osteogenesis and angiogenesis optimally. This biomimetic periosteum layer was integrated with artificial diaphysis made of tubular SF scaffolds to construct a biomimetic periosteum-diaphysis substitute. Animal studies confirmed that the biomimetic periosteum-diaphysis substitutes promoted the repair of critical-size bone defects of rabbit radius. Furthermore, the transplanted biomimetic periosteum-diaphysis substitute could prevent the growth of fibrous tissues in the bone defect, and thus reduce the occurrence of nonunion. This study described a promising tissue engineering strategy for the repair of large segmental bone defects.

DESIGN AND STUDY OF DIFFERENT SILK FIBROIN STRUCTURES

Abstract Introduction Tissue engineering (TE) has the capacity to design structures very similar to native tissues in order to restore, maintain or improve their biological functions. Silk fibroin (SF) is a natural protein that has been used in a wide variety of TE applications. Each SF structure has different mechanical and biological characteristics depending on the morphology and methodology employed. Methods Bombyx mori silkworm cocoons were extracted and processed to obtain SF. Subsequently, films, porous membranes, and electrospun membranes were designed using doctor blade, salt leaching, and electrospinning methodologies, respectively. Furthermore, electrospun SF membranes were developed according to the direction of the strands, obtaining membranes that were oriented as well as with random orientation. All these morphologies were subjected to mechanical, cytotoxicity and degradation studies. Results The most fragile SF structures were the films and the porous membranes, which underwent a maximum modification of approximately 5% with respect to their original size. However, electrospun membranes underwent a change in size of more than 20%. All SF morphologies had biocompatibility values close to 100%. Finally, there was a degradability between 3–5% at 4 weeks in all structures. Conclusions SF has very good mechanical characteristics when designed by electrospinning techniques. Although SF is biocompatible, there is a degradation of the material, which may affect the mechanical properties of the designed structure.

Silk Fibroin Combined with Electrospinning as a Promising Strategy for Tissue Regeneration.

The development of tissue engineering scaffolds is of great significance for the repair and regeneration of damaged tissues and organs. Silk fibroin (SF) is a natural protein polymer with good biocompatibility, biodegradability, excellent physical and mechanical properties and processability, making it an ideal universal tissue engineering scaffold material. Nanofibers prepared by electrospinning have attracted extensive attention in the field of tissue engineering due to their excellent mechanical properties, high specific surface area, and similar morphology as to extracellular matrix (ECM). The combination of silk fibroin and electrospinning is a promising strategy for the preparation of tissue engineering scaffolds. In this review, the research progress of electrospun silk fibroin nanofibers in the regeneration of skin, vascular, bone, neural, tendons, cardiac, periodontal, ocular and other tissues is discussed in detail.

Extracellular matrix sheet modified with VEGF-loaded nanoparticles for bladder regeneration

Extracellular matrix (ECM) bioscaffolds have been widely studied to repair bladder tissue defects; however, insufficient angiogenesis and weak mechanical strength limit their applicability for tissue regeneration. In this work, ECM bioscaffolds were derived from decellularized sheets and then modified with vascular endothelial growth factor (VEGF)-conjugated superparamagnetic iron oxide nanoparticles (Fe3O4 NP–VEGF) to promote angiogenesis. Electrospun silk fibroin (SF) is a natural biocompatible protein with excellent mechanical properties. To further improve the mechanical properties of ECM bioscaffolds, SF was added to the Fe3O4 NP–VEGF-modified ECM bioscaffolds to develop a biomimetic ECM-like proangiogenic scaffold. In vitro characterization with endothelial cells revealed that the proangiogenic scaffold supports cell adhesion and proliferation. Furthermore, the biomimetic proangiogenic scaffold significantly accelerated vascularization in vivo in a rat bladder augmentation model. Importantly, these improvements in vascularization promoted urothelium and smooth muscle regeneration. These findings demonstrate that the developed biomimetic proangiogenic scaffold possesses great potential for bladder regeneration applications.

Electrospun silk fibroin and gelatin blended nanofibers functionalized with noble metal nanoparticles for enhanced biomedical applications

The combination of highly anticancer active platinum group metals and biocompatible natural fibers exhibits significant anticancer activity while also allowing cell regeneration and repair to the damaged region. In this research, platinum and palladium nanoparticles anchored silk fibroin and gelatin (SF/GL/Pd-Pt) hybrid composite nanofiber was fabricated through the electrospinning method. The amino groups in SF and GL act as a reducingd stabilizing agent for the resulting Pd and Pt nanoparticles. Morphological and functional studies confirmed that crystalline Pd and Pt nanoparticles with average sizes of 5.11 and 3.03 nm are anchored on a 154.93 ± 34.19 nm SF/GL nanofiber matrix. The atomic force microscopic (AFM) images show that the SF/GL/Pd-Pt composite nanofiber has a thickness of 4.74 nm and a roughness area (Ra) of 258.5 nm. X-ray photoelectron spectroscopic (XPS) results confirmed the presence of C, N, O, Pt, and Pd in the composite fiber with an atomic percentage of 67.56%, 11.05%, 17.72%, 2.01% and 1.66%. respectively. This SF/GL/Pd-Pt composite nanofiber is more effective than its counterparts in terms of anticancer activity (IC50 value of 28.82 µg/mL−1) against A549 human lung carcinoma cells. Furthermore, the β-actin and Hsp90 gene expression in A549 cells confirmed its superior anticancer activity.

Electrochemical and Electroconductive Behavior of Silk Fibroin Electrospun Membrane Coated with Gold or Silver Nanoparticles.

The surface modification of materials obtained from natural polymers, such as silk fibroin with metal nanoparticles that exhibit intrinsic electrical characteristics, allows the obtaining of biocomposite materials capable of favoring the propagation and conduction of electrical impulses, acting as communicating structures in electrically isolated areas. On that basis, this investigation determined the electrochemical and electroconductive behavior through electrochemical impedance spectroscopy of a silk fibroin electrospun membrane from silk fibrous waste functionalized with gold or silver nanoparticles synthetized by green chemical reduction methodologies. Based on the results obtained, we found that silk fibroin from silk fibrous waste (SFw) favored the formation of gold (AuNPs-SFw) and silver (AgNPs-SFw) nanoparticles, acting as a reducing agent and surfactant, forming a micellar structure around the individual nanoparticle. Moreover, different electrospinning conditions influenced the morphological properties of the fibers, in the presence or absence of beads and the amount of sample collected. Furthermore, treated SFw electrospun membranes, functionalized with AuNPs-SFw or AgNPS-SFw, allowed the conduction of electrical stimuli, acting as stimulators and modulators of electric current.

Instructive electroactive electrospun silk fibroin-based biomaterials for peripheral nerve tissue engineering.

Aligned sub-micron fibres are an outstanding surface for orienting and promoting neurite outgrowth; therefore, attractive features to include in peripheral nerve tissue scaffolds. A new generation of peripheral nerve tissue scaffolds is under development incorporating electroactive materials and electrical regimes as instructive cues in order to facilitate fully functional regeneration. Herein, electroactive fibres composed of silk fibroin (SF) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) were developed as a novel peripheral nerve tissue scaffold. Mats of SF with sub-micron fibre diameters of 190±50nm were fabricated by double layer electrospinning with thicknesses of ∼100μm (∼70-80μm random fibres and ∼20-30μm aligned fibres). Electrospun SF mats were modified with interpenetrating polymer networks (IPN) of PEDOT:PSS in various ratios of PSS/EDOT (α) and the polymerisation was assessed by hard X-ray photoelectron spectroscopy (HAXPES). The mechanical properties of electrospun SF and IPNs mats were characterised in the wet state tensile and the electrical properties were examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The cytotoxicity and biocompatibility of the optimal IPNs (α=2.3 and 3.3) mats were ascertained via the growth and neurite extension of mouse neuroblastoma x rat glioma hybrid cells (NG108-15) for 7days. The longest neurite outgrowth of 300μm was observed in the parallel direction of fibre alignment on laminin-coated electrospun SF and IPN (α=2.3) mats which is the material with the lowest electron transfer resistance (Ret, ca. 330Ω). These electrically conductive composites with aligned sub-micron fibres exhibit promise for axon guidance and also have the potential to be combined with electrical stimulation treatment as a further step for the effective regeneration of nerves.

Zwitterionic keratin coating on silk-Laponite fibrous membranes for guided bone regeneration.

Implant-related infection is one of the main challenges in periodontal diseases. According to the zwitterionic properties of keratin, we aim to develop guided bone regeneration (GBR) membrane with antibacterial and bioactivity properties using a keratin coating. In this study, electrospun silk fibroin (SF)-Laponite (LAP) fibrous membranes were developed as GBR membranes, and keratin extracted from sheep wool was electrosprayed on them. Here, the role of electrospraying time (2, 3, and 4h) on the properties of the GBR membranes was investigated. After physicochemical characterization of the keratin-modified membranes, in vitro bioactivity and degradation rate of the membranes were studied in simulated body fluid and phosphate buffer saline, respectively. Moreover, proliferation and differentiation of mesenchymal stem cells were evaluated in contact with the keratin-modified SF-LAP membrane. Finally, the antibacterial activity of membranes against gram-positive bacteria (Staphylococcus aureus) was investigated. Results demonstrated the successful formation of homogeneous wool keratin coating on SF-LAP fibrous membranes using a simple electrospray process. While wool keratin coating significantly enhanced the elongation and hydrophilicity of the SF-LAP membrane, the mechanical strength was not changed. In addition, keratin coating significantly improved the bioactivity and degradation rate of SF-LAP membranes, owing to the carboxyl groups of amino acids in keratin coating. In addition, the synergic role of LAP nanoparticles and keratin coating drastically improved osteoblast proliferation and differentiation. Finally, the zwitterionic property of wool keratin coating originating from their equal positive (NH3 + ) and negative (COO- ) charges considerably improved the antibacterial activity of the SF-LAP membrane. Overall, keratin-coated SF-LAP fibrous membranes with significant mechanical and biological properties could have the potential for GBR membranes.