Silk fibroin-derived electrospun materials for biomedical applications: A review

Multifunctional applications of silk fibroin in biomedical engineering: A comprehensive review on innovations and impact

Silk fibroin (SF) is a biomaterial naturally produced by certain insects (notably silkworms), animals such as spiders, or through recombinant methods in genetically modified organisms. Its exceptional mechanical properties, biocompatibility, degradability, and bioactivity have inspired extensive research. In biomedicine, SF has been utilized in various forms, including gels, membranes, microspheres, and more. It also demonstrates versatility for applications across medical devices, regenerative medicine, tissue engineering, and related fields. This review explores the current research status, advantages, limitations, and potential application pathways of SF in biomedical engineering. The objective is to stimulate innovative ideas and perspectives for research and applications involving silk.

Advanced nanofibers integrating vitamin D3 and cerium oxide nanoparticles for enhanced diabetic wound healing: Co-electrospun silk fibroin-collagen and chitosan-PVA systems

This study investigates the co-electrospinning of polyvinyl alcohol-chitosan (PVA-CS) with cerium oxide nanoparticles (CeNPs) and silk fibroin-collagen (SF-Col) with vitamin D3 for diabetic wound healing applications. The SEM results showed smooth, bead-free nanofiber structures. The diameters of the SF-Col and PVA-CS nanofibers ranged from 168 ± 51 nm to 1956 ± 450 nm and 211.4 ± 37.2 nm, respectively. By surface modification using fetal bovine serum (FBS), CeNPs dispersion was enhanced. The average diameter of the uniformly distributed fibers on the SF-Co-D/PVA-CS-CeNPs nanofibers was 621.4 ± 50.6 nm. The addition of CeNPs and vitamin D3 improved cytocompatibility at lower doses. The FTIR test confirmed polymer interactions. Contact angle measurements indicated increased hydrophilicity. SEM analysis demonstrated excellent adhesion and growth of L929 fibroblast cells and significant HUVEC migration on SF-Col-D/PVA-CS-CeNP mats, emphasizing their potential to support cell proliferation and tissue regeneration. Blood compatibility assays exhibited hemolysis percentages below 2 %, classifying the nanofibers as non-hemolytic. Antibacterial tests revealed significant reductions in Staphylococcus aureus and Pseudomonas aeruginosa survival, addressing infection concerns in chronic wounds. Furthermore, in vivo studies have demonstrated that the utilization of SF-Co-D/PVA-CS-CeNPs nanofibrous membrane as a dressing for full-thickness skin wounds in rats has resulted in accelerated tissue regeneration.

Preparing the functional biomaterial with osteogenic bioactivities by incorporating annealing pretreated silk fiber and iron oxide nanoparticles

Silk fiber (SF), a kind of bio-fiber from biomass protein fibers with biocompatibility and mechanical properties, has been widely utilized in biomedical engineering. However, SF-based bio-scaffolds often encounter challenges in promoting osteogenesis within bone tissue engineering (BTE) applications. In this study, SF-based composites were constructed via the solution casting method in the presence of IONPs (SFFC-IONPs), followed by annealing-induced self-assembly to form magnetic SF annealing films (SFFCA-IONPs). Three types of IONPs loaded SF films (SFFCA-50, SFFCA-100, and SFFCA-200) were prepared by altering the feeding IONPs (50 μg/mL, 100 μg/mL, and 200 μg/mL). Results demonstrated that SFFC films primarily exhibited random coil structures and were water-soluble, while SFFCA films demonstrated the formation of silk II structures and became water-insoluble. The incorporation of IONPs significantly enhanced the porosity, mechanical strength, and thermal stability of the SFFCA films. Furthermore, the SFFCA-IONPs films not only exhibited excellent biocompatibility but also demonstrated enhanced osteo-inductive properties, as evidenced by increased alkaline phosphatase (ALP) activity, enhanced mineralized nodule formation, and upregulation of osteogenic gene expression. This study presents a promising bio-based material with significant potential for use as a scaffold in BTE applications.

Review on application of silk fibroin hydrogels in the management of wound healing

Wounds are regarded as disruptions in the integrity of human skin tissues, and the process of wound healing is often characterized as protracted and complex, primarily due to the potential infection or inflammation caused by microorganisms. The quest for innovative solutions that accelerate wound healing while prioritizing patient safety and comfort has emerged as a focal point. Within this pursuit, silkworm silk fibroin-a natural polymer extracted from silk cocoons-exhibits a distinctive combination of properties including biocompatibility, biodegradability, superior mechanical strength, water absorption, and low immunogenicity, which align closely with the demands of contemporary wound care. Its remarkable biocompatibility facilitates seamless integration with host tissues, thereby minimizing the risk of rejection or adverse reactions. Furthermore, its intrinsic degradability permits controlled release of therapeutic agents, promoting an optimal microenvironment conducive to healing. This review investigates the multifaceted potential of silk fibroin specifically as a wound dressing material and examines the intricate nuances associated with its application in hydrogels for wound healing, aiming to furnish a thorough overview for both researchers and clinicians. By scrutinizing underlying mechanisms, current applications, and prospective directions, we aspire to cultivate new insights and inspire innovative strategies within this rapidly evolving field.

Silk Protein Gene Engineering and Its Applications: Recent Advances in Biomedicine Driven by Molecular Biotechnology

Silk protein, as a natural polymer material with unique structures and properties, exhibits tremendous potential in the biomedical field. Given the limited production and restricted properties of natural silk proteins, molecular biotechnology has been extensively applied in silk protein genetic engineering to produce novel silk proteins with specific properties. This review outlines the roles of major model organisms, such as silkworms and spiders, in silk protein production, and provides a detailed introduction to the applications of gene editing technologies (eg, CRISPR-Cas9), transgenic expression technologies, and synthetic biology techniques in silk protein genetic engineering. By analyzing the genetic factors influencing silk protein expression, this review further elaborates on the innovative applications of silk proteins in drug delivery systems, tissue engineering and regenerative medicine (eg, skin, bone, cartilage, and vascular repair), as well as antibacterial immune strategies. Notably, modified silk proteins expressed by transgenic silkworms demonstrate significant advantages in enhancing drug bioavailability and promoting cell proliferation and differentiation. In conclusion, silk protein gene engineering, through continuous innovations in molecular biotechnology, has provided an effective pathway for the production of high-performance silk protein materials. The extensive applications of these modified silk proteins in the biomedical field have not only expanded the functionality of silk proteins but also offered new approaches to address medical challenges. In the future, the development of silk protein gene engineering will further rely on interdisciplinary integration to promote in-depth research and the expansion of industrial applications of silk proteins.

Natural Protein Films from Textile Waste for Wound Healing and Wound Dressing Applications

In recent years, several studies have focused on the development of sustainable, biocompatible, and biodegradable films with potential applications in wound healing and wound dressing systems. Natural macromolecules, particularly proteins, have emerged as attractive alternatives to synthetic polymers due to their biocompatibility, biodegradability, low immunogenicity, and adaptability. Among these proteins, keratin, extracted from waste wool, and fibroin, derived from Bombyx mori cocoons, exhibit exceptional properties such as mechanical strength, cell adhesion capabilities, and suitability for various fabrication methods. These proteins can also be functionalized with antimicrobial, antioxidant, and anti-inflammatory compounds, making them highly versatile for biomedical applications. This review highlights the promising potential of keratin- and fibroin-based films as innovative platforms for wound healing, emphasizing their advantages and the prospects they offer in creating next-generation wound dressing devices.

Advanced applications of smart electrospun nanofibers in cancer therapy: With insight into material capabilities and electrospinning parameters

Cancer remains a major global health challenge, and despite available treatments, its prognosis remains poor. Recently, researchers have turned their attention to intelligent nanofibers for cancer drug delivery. These nanofibers exhibit remarkable capabilities in targeted and controlled drug release. Their inherent characteristics, such as a high surface area-to-volume ratio, make them attractive candidates for drug delivery applications. Smart nanofibers can release drugs in response to specific stimuli, including pH, temperature, magnetic fields, and light. This unique feature not only reduces side effects but also enhances the overall efficiency of drug delivery systems. Electrospinning, a widely used method, allows the precision fabrication of smart nanofibers. Its advantages include high efficiency, user-friendliness, and the ability to control various manufacturing parameters. In this review, we explore the latest developments in producing smart electrospun nanofibers for cancer treatment. Additionally, we discuss the materials used in manufacturing these nanofibers and the critical parameters involved in the electrospinning process.

Biomimetic conjugation inspired from pheomelanin via thiol-quinone addition for enzymatic functionalization of fibroin

Fibroin has been extensively applied in the medicine, therapy, cosmetic, and food fields. Functional modification is a common route way to expand the application potential. Tyrosinase is versatile for enzymatic functionalization of fibroin by oxidizing tyrosine residues into dopaquinone. However, grafting of functional molecules to the protein-bound dopaquinone suffers from self-crosslinking due to competitive aryl coupling or addition with other nucleophile in protein. Herein, bioinspired from pheomelanin synthesis, a new approach with superior grafting efficiency and reaction rate for enzymatic grafting of protein was developed. The high reactivity of Michael addition between thiol and dopaquinone was utilized to promote the efficiency for grafting of PEG onto fibroin. The grafting of PEG with thiol group was superior to that with amine group. It demonstrated a superior efficacy for thiol group over amino group on enzymatic functionalization. This research firstly established an effective biomimetic approach for enzymatic functionalization of protein without the unexpected self-crosslinking. It could emerged to serve as the strategy of protein functionalization.

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

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 scaffolds (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.

Research Advances in Electrospun Nanofiber Membranes for Non-Invasive Medical Applications

Non-invasive medical nanofiber technology, characterized by its high specific surface area, biocompatibility, and porosity, holds significant potential in various medical domains, including tissue repair and biosensing. It is increasingly becoming central to healthcare by offering safer and more efficient treatment options for contemporary medicine. Numerous studies have explored non-invasive medical nanofibers in recent years, yet a comprehensive overview of the field remains lacking. In this paper, we provide a comprehensive summary of the applications of electrospun nanofibers in non-invasive medical fields, considering multiple aspects and perspectives. Initially, we introduce electrospinning nanofibers. Subsequently, we detail their applications in non-invasive health, including health monitoring, personal protection, thermal regulation, and wound care, highlighting their critical role in improving human health. Lastly, this paper discusses the current challenges associated with electrospun nanofibers and offers insights into potential future development trajectories.

Recombinant fibrous protein biomaterials meet skin tissue engineering

Natural biomaterials, particularly fibrous proteins, are extensively utilized in skin tissue engineering. However, their application is impeded by batch-to-batch variance, limited chemical or physical versatility, and environmental concerns. Recent advancements in gene editing and fermentation technology have catalyzed the emergence of recombinant fibrous protein biomaterials, which are gaining traction in skin tissue engineering. The modular and highly customizable nature of recombinant synthesis enables precise control over biomaterial design, facilitating the incorporation of multiple functional motifs. Additionally, recombinant synthesis allows for a transition from animal-derived sources to microbial sources, thereby reducing endotoxin content and rendering recombinant fibrous protein biomaterials more amenable to scalable production and clinical use. In this review, we provide an overview of prevalent recombinant fibrous protein biomaterials (collagens, elastin, silk proteins and their chimeric derivatives) used in skin tissue engineering (STE) and compare them with their animal-derived counterparts. Furthermore, we discuss their applications in STE, along with the associated challenges and future prospects.

Review of Spider Silk Applications in Biomedical and Tissue Engineering

This review will present the latest research related to the production and application of spider silk and silk-based materials in reconstructive and regenerative medicine and tissue engineering, with a focus on musculoskeletal tissues, and including skin regeneration and tissue repair of bone and cartilage, ligaments, muscle tissue, peripheral nerves, and artificial blood vessels. Natural spider silk synthesis is reviewed, and the further recombinant production of spider silk proteins. Research insights into possible spider silk structures, like fibers (1D), coatings (2D), and 3D constructs, including porous structures, hydrogels, and organ-on-chip designs, have been reviewed considering a design of bioactive materials for smart medical implants and drug delivery systems. Silk is one of the toughest natural materials, with high strain at failure and mechanical strength. Novel biomaterials with silk fibroin can mimic the tissue structure and promote regeneration and new tissue growth. Silk proteins are important in designing tissue-on-chip or organ-on-chip technologies and micro devices for the precise engineering of artificial tissues and organs, disease modeling, and the further selection of adequate medical treatments. Recent research indicates that silk (films, hydrogels, capsules, or liposomes coated with silk proteins) has the potential to provide controlled drug release at the target destination. However, even with clear advantages, there are still challenges that need further research, including clinical trials.