Tunable Light-Actuated Interpenetrating Networks of Silk Fibroin and Gelatin for Tissue Engineering and Flexible Biodevices

Visible Light Cross-Linked Methacrylated Silk Fibroin Enables Enhanced Osteogenic Response in Bioprinted Dual-Layer Guided Bone Regeneration Membrane

Precise design and fabrication of photo-cross-linked hydrogels with controlled network architecture and tailored mechanical properties are essential for advancing complex tissue engineering applications. In this study, a visible-light-activated type II photo-cross-linking system was developed using eosin Y/triethanolamine/N-vinylpyrrolidone (VE) to fabricate methacrylated silk fibroin (SFM) hydrogels through oxygen-mediated controlled photolysis. In comparison to conventional UV-initiated lithium phenyl-2,4,6-trimethylbenzoylphosphinate cross-linking, which rapidly yields mechanically stiffer networks with pronounced β-structures, the VE system (0.02 mM eosin Y, 100 mM triethanolamine, and 50 mM N-vinylpyrrolidone) enabled the fabrication of gradually formed compliant homogeneous networks. This tunability allowed using VE cross-linked SFM in light-assisted extrusion bioprinting to fabricate a dual-layer guided bone regeneration membrane incorporating a collagen I-rich ECM layer. Under calcium-supplemented conditions, the dual-layer membrane exhibited robust osteogenic potential, evidenced by significantly elevated ALP activity and distinctive nodular mineralization patterns compared with single-layer controls. Gene expression profiles revealed coordinated regulation of early (RUNX2, COL1A1), mid-to-late (SPP1, SPARC), and late-stage (BGLAP) markers, indicating successful progression through the osteogenic program. The heterogeneous design achieved a desired balance between its barrier function and tissue integration with an interconnected porous architecture that limits soft tissue downgrowth while supporting matrix organization conducive to bone regeneration. These findings establish critical structure-function relationships in photo-cross-linked biomaterials and highlight how mechanistic understanding of cross-linking chemistry can guide the rational design of functional scaffolds for biomedical applications.

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.

Functional electrospun nanofibers: fabrication, properties, and applications in wound-healing process

Electrostatic spinning as a technique for producing nanoscale fibers has recently attracted increasing attention due to its simplicity, versatility, and loadability. Nanofibers prepared by electrostatic spinning have been widely studied, especially in biomedical applications, because of their high specific surface area, high porosity, easy size control, and easy surface functionalization. Wound healing is a highly complex and dynamic process that is a crucial step in the body's healing process to recover from tissue injury or other forms of damage. Single-component nanofibers are more or less limited in terms of structural properties and do not fully satisfy various needs of the materials. This review aims to provide an in-depth analysis of the literature on the use of electrostatically spun nanofibers to promote wound healing, to overview the infinite possibilities for researchers to tap into their biomedical applications through functional composite modification of nanofibers for advanced and multifunctional materials, and to propose directions and perspectives for future research.