Infection Micromilieu-Activated Nanocatalytic Membrane for Orchestrating Rapid Sterilization and Stalled Chronic Wound Regeneration

Pathogenic infection inevitably provokes chronic inflammation and stalls the normal orchestrated course of wound-healing cascades. However, current antibacterial therapies focus on the inherent bactericidal functions of biomaterials. To take full advantage of infection microenvironment (IME) peculiarities, an IME-activated nanocatalytic membrane consisting of electrospun poly (lactic-co-glycolic acid) (PLGA) scaffolds, MXene/Ag2S bio-heterojunctions (MX/AS bio-HJs), and lactate oxidase (LOx) for chronic cutaneous regeneration is devised and developed. In this intelligent system, PLGA membranes gradually degrade to lactate, and LOx consumes lactate to yield abundant hydrogen peroxide (H2O2) in a microenvironment-responsive manner. In addition, MX/AS bio-HJs in membranes not only exert benign photothermal effects and generate reactive oxygen species upon NIR light, but also catalyze the produced H2O2 to overwhelming hydroxyl radicals (center dot OH) through Fenton-like reactions, which all result in rapid synergistic sterilization. Furthermore, in vivo assays demonstrate that the nanocatalytic membranes reshape the stalled chronic wound into a regenerative wound by massacring bacteria, stopping bleeding, boosting epithelialization/collagen deposition of the wound beds, and promoting angiogenesis. As envisaged, the proposed tactic opens up a promising opportunity for arming membranes with IME-responsive nanocatalytic activity to remedy bacteria-invaded stalled full-thickness wounds.

Automated summary

The study presents a nanocatalytic membrane activated by the infection microenvironment (IME) to promote chronic skin regeneration through leveraging the peculiarities of the IME, with functions including sterilization, hemostasis, promotion of epithelialization/collagen deposition, and angiogenesis in wound healing.