Effect of Gamma Ray Sterilization on the Properties of Three-Dimensional Printed Chitosan-Bioactive Glass Scaffolds for Peripheral Nerve Tissue Engineering.

Sterilization is a prerequisite for the clinical use of medical devices. Gamma irradiation is a high-penetrating, low-temperature process used in biomaterials. However, it can alter materials' properties, potentially changing their functional performance. In this study, three dimensional (3D)-printed chitosan-bioactive glass scaffolds were processed with clinically relevant gamma irradiation doses (15 and 25 kGy) and evaluated for nerve tissue engineering. Physicochemical characterizations were performed using FTIR, DSC, SEM, mechanical testing, swelling, and degradation assays. Biological performance was assessed with relevant cell lines using indirect cytotoxicity assays, complemented by adhesion and morphological analyses. FTIR and DSC analyses suggested changes consistent with simultaneous irradiation-induced structure rearrangement and enhanced intermolecular interactions. These events enhanced mechanical properties, reduced fluid uptake, and slowed scaffold degradation. Furthermore, high cell viability and adhesion showed that cytocompatibility was preserved. Overall, gamma radiation can be used not only for sterilization but also to improve the scaffold's structural and mechanical integrity, supporting its potential for nerve tissue engineering applications.