Title : Biocompatibility and subcutaneous host response to silk fibroin–chitosan composite plugs: Progress toward biodegradable implant materials
Abstract:
Silk fibroin (SF) and chitosan (CS) are promising biopolymers for biodegradable scaffolds in regenerative therapies. Here, we produced SF/CS composite plugs at 70:30 and 60:40 ratios and compared them to single-polymer controls to examine their physicochemical traits and preliminary biocompatibility. ATR-FTIR spectra confirmed both polymers in the blends and showed band broadening and shifts indicative of increased intermolecular hydrogen bonding. Thermal analyses (DSC/TGA) demonstrated improved thermal resistance in SF-dominant formulations, while SEM imaging revealed that blended fibers had smoother, more uniform surfaces. In vitro assays using macrophages (J-774A.1) and fibroblasts (HFF-1) indicated robust metabolic activity across all SF/CS samples, with the 60:40 formulation performing best. Subcutaneous implantation in mice produced a controlled foreign-body response marked by granulomatous inflammation, fibrosis, and new blood vessel formation, without acute adverse effects. Overall, SF/CS blends—notably the 60:40 ratio—offer adjustable structural and thermal properties along with early biocompatibility that support their potential as biodegradable implantable materials. Additional work in defect-specific in vivo models is necessary to establish application-specific performance and translational potential.
