The preparation of 3D-printed self-healing hydrogels composed of carboxymethyl chitosan and oxidized dextran via stereolithography for biomedical applications.

This study presents a new approach for fabricating 3D-printed self-healing hydrogels via light-assisted 3D printing, utilizing Schiff-base and covalent bonding formations resulting from the reaction between amine and aldehyde functional groups alongside the photopolymerization of methacrylate groups. Two distinct polymers, carboxymethyl chitosan (CMCs) and dextran, were first modified to yield methacrylate-modified carboxymethyl chitosan (CMCs-MA) and oxidized dextran (OD). The structural modifications of these polymers were confirmed using spectroscopic techniques, including H NMR and FTIR analyses. Variations in polymer concentration and degree of oxidation resulted in significant differences in the physical properties of resulting hydrogels (e.g., mechanical performance, swelling ratio, and microstructure) and biological responses. The compressive moduli revealed in the range of 14.31 ± 1.38 to 26.20 ± 3.31 kPa. Chondrocytes cultured with various hydrogel formulations exhibited distinct cell morphology and adhesion differences, driven by the interaction between the mechanical and biochemical properties of the hydrogel. We have developed a strategy for fabricating 3D-printed self-healing hydrogels with tunable stiffness, enabling the regulation of chondrocyte morphology and demonstrating significant potential for biomedical applications.