Title: Cytocompatibility and subcutaneous host response of silk fibroin–chitosan composite plugs: Toward resorbable implantable materials
Abstract:
Silk fibroin (SF) and chitosan (CS) are biopolymers widely studied as resorbable scaffolds for regenerative medicine. In this study, SF/CS composite plugs were prepared at 70:30 and 60:40 ratios and compared with single-polymer controls to evaluate their physicochemical properties and preliminary biocompatibility. ATR-FTIR confirmed the presence of both components in the composites and showed band broadening and shifts consistent with increased intermolecular hydrogen bonding. Thermal analysis (DSC/TGA) indicated greater thermal stability in SF-rich formulations, while SEM revealed smoother, more homogeneous morphologies in the blended fibers. In vitro cytocompatibility assays with macrophages (J-774A.1) and fibroblasts (HFF-1) showed high metabolic activity in all SF/CS groups, with the 60:40 blend being the most favorable. Subcutaneous implantation in mice elicited a controlled foreign-body reaction characterized by granulomatous inflammation, fibrosis, and neovascularization, without signs of acute adverse responses. Together, these results indicate that SF/CS blends—particularly at 60:40—exhibit tunable structural and thermal properties and early-stage biocompatibility supportive of their use as resorbable implantable biomaterials. Further studies in defect-specific models are needed to determine application-dependent performance and translational readiness.
