Multifunctional Polyoxovanadate-Based\nCovalent Organic\nPolymer for Bacteria-Infected Wound Therapy

The special pathological microenvironment of infected\nwounds (pathology\nof weakly acidic, hypoxic, and overexpressed H<sub>2</sub>O<sub>2</sub>) provides fertile soil for the development of disease. Tailoring\ntreatment based on the specific characteristics of the infectious\nmicroenvironment (IME) has emerged as a novel direction in the development\nof antimicrobial therapies. Here, a polyoxovanadate (POV)-based covalent\norganic polymer (POV-Fc-COP) with inherent photothermal activity was\nfacilely prepared via the copolymerization of 1,1′-bi(3-dimethylamino-1-oxo-2-enyl-ferrocene)\n(BDOEF) with tris-NH<sub>2</sub>-modified POV (tris-V<sub>6</sub>O<sub>9</sub>), in which the nanovanadium oxide (V<sub>2</sub>O<sub>3</sub> and V<sub>2</sub>O<sub>5</sub>) core and polymer shell were generated\ndirectly during the Michael addition–elimination reaction.\nThe unique structure and composition impart pH-responsive peroxidase-like\n(POD-like) and catalase-like (CAT-like) activities, concurrently,\nto the POV-Fc-COP. Specifically, the acid-activated mimicking-POD\nactivity could consume H<sub>2</sub>O<sub>2</sub> in the microenvironment,\nproducing toxic •OH to combat bacteria and biofilms. The vanadium\noxide consumes the excessive acid, resulting in an increase in pH.\nMeanwhile, the CAT-like activity could transform excess H<sub>2</sub>O<sub>2</sub> expression into O<sub>2</sub> to relieve hypoxia induced\nby the damage of blood vessels in the wounds and facilitate wound\nhealing. Additionally, the synergistic amplified therapeutic effect\ntriggered by the application of laser irradiation facilitates the\nrapid eradication of bacteria and biofilm, minimizing the detrimental\nimpacts of bacterial proliferation on the IME, thereby accelerating\nthe restoration of the IME return to a normal state. Therefore, POV-Fc-COP\nwith a dual-enzyme functionality could not only utilize but also regulate\nthe IME, significantly expediting the healing of bacteria-infected\nwounds. This study demonstrates a simple method for the preparation\nof an intelligent platform for programmed antibacterial and antibiofilm\nformation, thus promoting healing while utilizing and improving the\nIME.