H₂O₂ Self-Supplied MoS₂/CaO₂ Nanozyme Hydrogel with Near-Infrared Photothermal Synergetic Cascade Peroxidase-Like Activity for Wound Disinfection.

Abstract

In wound healing and clinical anti-infection therapy, the current feasibility of nanocatalysts is extremely limited because of inadequate reactive oxygen species (ROS) generation. Herein, a novel H₂O₂ self-supplying nanocomposite (M/C/AEK) consists of molybdenum disulfide (MoS₂) decorated with calcium peroxide (CaO₂) prepared at ambient temperature and encapsulated in AEK hydrogel. In the presence of H₂O₂ and poly(vinyl pyrrolidone) (PVP), CaO₂ nanoclusters, ≈30 nm, are anchored on the MoS₂ surface. MoS₂/CaO₂ can induce both a cascaded peroxidase (POD)-like and catalase (CAT)-like catalytic activity to produce toxic hydroxyl radicals through self-supplied H₂O₂ and O₂ responsive to the faintly acidic environment of acute wounds. The POD-like activity is increased under acidic compared with neutral conditions, allowing selective treatment of acute, slightly acidic wounds while avoiding the side effects of high-concentration antibacterial agents on normal tissues. The high near-infrared photothermal effect synergistically with POD-like/CAT-like activity of MoS₂/CaO₂ boosts the production of more ROS to eradicate Staphylococcus aureus and Escherichia coli bacteria (98.6% and 98.9%) effectively and selectively stimulate wound healing. The porous M/C/AEK hydrogel in the wound microenvironment can efficiently capture bacteria, and its Ca²⁺ ions and keratin stimulate healing, revealing excellent potential in advanced wound care and infection control therapies.