Fast-gelling Polyethylene Glycol/Polyethyleneimine Hydrogels Degradable by Visible-Light.

The treatment of burn wounds remains a clinical challenge due to the need for repeated dressings changes. Therefore, the development of a dressing system that can be atraumatically removed from the wound bed can be considered a breakthrough and improve treatment times. In this work, we propose the development of an injectable, fast-gelling hydrogel that can change its mechanical properties when exposed to visible light. The hydrogels w ere prepared by a "click" amino-yne reaction between poly(ethylene glycol) (PEG) functionalized with propiolic acid and the amino groups of poly(ethyleneimine) (PEI). The hydrogels exhibited a fast gelation time, which can be adjusted by changing the weight percentage and molecular weight of the precursors. They also exhibited good swelling ability and adhesion to living tissues. More importantly, their mechanical properties changed upon irradiation with green light LED. After two hours of irradiation, the hydrogels lost almost 50% of their maximum compressive stress and 69% of the original modulus for the hydrogel PEG 2k /PEI 1.8k 30 wt. %, and 26% of the original modulus for the hydrogel PEG 2k /PEI 0.6k 30 wt. %. This loss of properties was achieved by a 1 O 2 -mediated mechanism, as confirmed by the degradation of the β-aminoacrylate linker. Moreover, the in vitro cell compatibility results of the hydrogels and their degradation products showed good cytocompatibility. Therefore, we believe that these hydrogels can be considered as materials with great potential for an innovative strategy for the treatment of burn wounds. This article is protected by copyright. All rights reserved.