Biocompatible Photocrosslinked Chitosan- and Gelatin-Based Hydrogels for Wound Healing Applications

The study presents novel photocrosslinked hydrogels based on methacrylated chitosan and methacrylated gelatin/allyl-modified gelatin and compares their properties as drug delivery systems in wound healing applications. The polymers were selected due to their biocompatible, mucoadhesive, cell-interactive properties and flexibility in adjusting their structure, making them suitable candidates for applications that require tissue repair. A range of hydrogel formulations was obtained by modulating the ratio of modified chitosan to two distinct modified gelatins, with photocrosslinking performed using Irgacure 2959 as the photoinitiator. FT-IR analysis, SEM data, and swelling and mechanical properties confirmed the 3D networking and the compatibility between the hydrogel components. Allylic gelatin-based hydrogels present larger pores and a stronger pH-responsive swelling behaviour compared to methacrylated gelatin-based samples, reflecting the higher flexibility of allylic gelatin networks. The hydrogels release bacitracin during the first six hours, with a release profile that follows a non-Fickian diffusion mechanism. Cytocompatibility and wound healing potential were tested in the presence of human and mouse fibroblasts, cells with a pivotal role in the wound healing process. All formulated hydrogels exhibit antioxidant capacity and protein stabilization properties, which are attributed to the presence of chitosan in their composition. The cytocompatibility, in vitro wound healing, and biological properties of the obtained hydrogels, as well as the drug release results, confirm their suitability in wound healing applications.