Effects of Genipin Crosslinking on the Structural and Rheological Properties of Chitosan/Collagen Hydrogels for Biomedical Applications

Chitosan/collagen hydrogels have gained prominence in biomedical applications due to their biocompatibility and ability to promote tissue regeneration. However, rheological instability may limit their applicability. This study investigated the structural and rheological properties of chitosan/collagen hydrogels (99:1, 97:3, and 95:5%) crosslinked with 0.1% genipin. The samples were characterized by Fourier Transform Infrared Spectroscopy (FTIR), injectability, viscosity, swelling, biodegradation, and blood clotting time. Genipin crosslinking improved structural stability, increased viscosity and extrusion resistance, and provided slower and more predictable mass loss under physiological and enzymatic conditions. The swelling assay showed a progressive reduction in water uptake with increasing collagen content, further accentuated by genipin, suggesting a denser and more stable polymeric network. Additionally, the hydrogels accelerated blood coagulation, reinforcing their potential use as hemostatic agents.