Local Visible-Photocatalytic Production of Hydrogen and Warm Heat for Combination Treatment of Pressure Ulcer.

Pressure ulcer (PU) is hardly cured due to repeated pressures-induced serious ischemia-reperfusion injury (IRI), poor microcirculation, and chronical inflammation. Hydrogen molecule (H) is proved as an emerging anti-inflammatory and anti-IRI agent with high biological safety, while local warm heating is well identified and able to improve tissue microcirculation for promoting wound repair. This work proposes a new strategy of visible-photocatalytic hydrogen/warm heat production for combination treatment of PU, and develops palladium nanodots-deposited hydrogen-doped titanium dioxide nanorod (HTON-Pd) as a novel multifunctional photocatalyst, achieving controllable and sustainable visible-photocatalytic production of H and heat. Daily administration of the HTON-Pd encapsulated hydrogel dressing (HTON-Pd@Gel) with the assistance of visible light irradiation receives a high outcome of PU treatment. The stubborn PU wound has completely been cured after 11-day treatment with HTON-Pd@Gel. Mechanistically, hydrogen and warm heat photocatalytically produced by HTON-Pd improve the PU wound microenvironment by synergistically promoting the proliferation and migration of skin cells, inhibiting their apoptosis, reducing the inflammatory response, and boosting the generation of new blood vessels in support of PU wound healing.