Multi-responsive, injectable, and self-healing hydrogels based on benzoxaborole–tannic acid complexation

The plant-derived polyphenol tannic acid (TA) was used to crosslink linear statistical polymers containing benzoxaborole [poly(MPC-st-MAABO)] to form a bio-inspired, multi-responsive, injectable, and self-healing hydrogel in the physiological environment via benzoxaborole–tannic acid complexation. The mechanical properties of the hydrogel were easily tuned by adjusting the molar ratio between tannic acid and benzoxaborole groups. Fast degradation of the hydrogel was observed in the presence of fructose, adenosine 5′-triphosphate (ATP), and dopamine (catechol), and reversible sol–gel formation was induced by changing the pH of the hydrogel. As the hydrogel was crosslinked by dynamic boronic ester bonds, the self-healing property and injectability were expected and confirmed. 3D cell encapsulation within the hydrogel scaffold was successfully achieved. This technique offered a promising method for preparing bio-inspired, multi-responsive, injectable, and self-healing hydrogels to fulfill current demands in biomedical applications.