A Visible Light Cross‐Linked Underwater Hydrogel Adhesive with Biodegradation and Hemostatic Ability

Abstract Hydrogel adhesives with integrated functionalities are still required to match their ever‐expanding practical applications in the field of tissue repair and regeneration. A simple and effective safety strategy is reported, involving an in situ injectable polymer precursor and visible light‐induced cross‐linking. This strategy enables the preparation of a hydrogel adhesive in a physiological environment, offering wet adhesion to tissue surfaces, molecular flexibility, biodegradability, biocompatibility, efficient hemostatic performance, and the ability to facilitate liver injury repair. The proposed one‐step preparation process of this polymer precursor involves the mixing of gelatin methacryloyl (GelMA), poly(thioctic acid) [P(TA)], poly(acrylic acid)/amorphous calcium phosphate (PAAc/ACP, PA) and FDA‐approved photoinitiator solution, and a subsequent visible light irradiation after in situ injection into target tissues that resulted in a chemically‐physically cross‐linked hybrid hydrogel adhesive. Such a combined strategy shows promise for medical scenarios, such as uncontrollable post‐traumatic bleeding.