Comprehensive physicochemical, biocompatibility, and in vivo evaluation of a nanofiber gelatin bone graft matrix for bone tissue regeneration

Nanofiber-based biomaterials have emerged as promising bone tissue engineering scaffolds because they mimic the native extracellular matrix and promote bone regeneration. This study comprehensively evaluated the physicochemical properties, biocompatibility, and in vivo performance of a nanofiber gelatin bone graft matrix. Material characterization included fiber morphology, crystallographic structure, phase composition, porosity, specific surface area, and tensile strength. Biological safety was assessed through qualitative and quantitative in vitro cytotoxicity assays, biocompatibility testing, subchronic systemic toxicity, and an in vitro mammalian cell gene mutation assay. Bone regeneration and local tissue responses were evaluated using a rabbit distal femoral implantation model at 1, 3, and 6 months. The nanofiber gelatin matrix exhibited an average fiber diameter of 156.9 ± 26.0 nm, crystallinity of 97.3%, pore size of 182.4 ± 22.1 Å, specific surface area of 36.2 ± 2.5 m²/g, porosity of 67.0 ± 1.6%, and tensile strength of 59.1 ± 4.6 N/mm². No evidence of in vitro cytotoxicity, systemic toxicity, or mutagenicity was observed. Histopathological evaluation demonstrated no adverse local tissue response over the 182-day implantation period (implantation score < 2.9). In vivo, the nanofiber gelatin bone graft matrix showed bone regeneration and degradation characteristics comparable to those of the predicate device, Socko Graftend Collagen Bone Graft. These findings demonstrate that the nanofiber gelatinn bone graft matrix possesses favorable physicochemical properties, excellent biocompatibility, and effective bone regenerative performance, supporting its potential as a safe and effective scaffold for bone tissue engineering applications.