Hollow CuS immobilized in polysaccharide hydrogel promotes photothermally-driven vascularization

Overcoming drastic warming or preventing excessive Cu2+ aggregation is essential for the application of photoresponsive copper sulfide in tissue repair. Here, we prepared a photothermal hydrogel (HG@HCuS) dressing with hollow copper sulfide (HCuS) nanoparticle as the crosslinked core, along with mercapto gelatin and dopamine-coupled hyaluronan as the polymer substrates, which presented stable mechanical strength and controlled Cu2+ release. The HG@HCuS achieved mild photothermal conversion to prevent thermal damage, the temperature dropped to 42 ℃ in comparison with 55 ℃ in solid CuS under the irradiation of 1064 nm laser. The HG@HCuS enhanced the proliferation and migration of vascular endothelial cells, and promoted VEGF protein expression in vitro. Meanwhile, it acquired satisfactory repair capability in a 2 cm diameter wound by significantly inhibiting the inflammatory factors secretion, increasing the collagen deposition and blood vessel number of regenerative dermis. These results demonstrated that photothermally-driven HG@HCuS provide a new strategy for skin regeneration.