NMR-Based Crosslinking Kinetics in Methacrylated Biopolymers: Toward Optimized Biomaterials for Tissue Engineering...

The crosslinking rate of methacrylated biopolymer hydrogels critically influences the mechanical and biological performance of 3D scaffolds in tissue engineering and regenerative medicine. Precise characterization of crosslinking kinetics is therefore essential for optimizing biopolymers specifically for 3D bioprinting applications and elucidating molecular-level biomaterial processes. Additionally, understanding side reactions during photocuring is vital to control potential contamination in bioscaffold fabrication. This study utilizes nuclear magnetic resonance (NMR) spectroscopy as a rapid, reliable approach to monitor crosslinking kinetics by quantifying methacrylic group conversion, providing deeper insights into the crosslinking process and ensuring more reproducible and reliable outcomes. A comprehensive kinetic analysis distinguishes intra- and intermolecular crosslinking mechanisms through assessment of photoinitiator activation and by-product formation. Furthermore, NMR spectroscopy quantifies photoinitiator degradation products generated during photocuring. This investigation systematically examines the influence of photocrosslinking parameters-UV-visible light power and wavelength, prepolymer concentration, and photoinitiator concentration-on scaffold molecular organization. Results indicate significant variability in scaffold properties contingent upon the applied crosslinking conditions, emphasizing their importance in controlled polymerization environments. These mechanistic insights underline the practical relevance and application potential of the study, significantly advancing biomaterial performance, reproducibility, and biological safety, particularly in translational and implementation-focused research.