Iodine has been successed in combating bacteria over a century, but its toxic effects on human skin tissues and cells have been overlooked. In this work, a cow dung biochar-based polyvinyl alcohol/polyvinylpyrrolidone hydrogel (BCPP) was designed to in situ produce iodine on-demand and regulate its release via the light triggering strategy for the infected wound therapy. Benefiting from the reactive oxygen species (ROS) generation and the photothermal conversion properties of cow dung biochar (BC), the as-prepared hydrogel in situ transformed iodide into active iodine under the visible (Vis) light irradiation and regulated the release of active iodine under the near-infrared (NIR) light irradiation. The active iodine combined with photodynamic and photothermal effects of BCPP endowed hydrogel excellent antibacterial effects on ampicillin-resistant Escherichia coli (AREC) and methicillin-resistant Staphylococcus aureus (MRSA) while showing low toxicity to the mammalian cells. The in vivo wound therapy test results demonstrated that this hydrogel resisted MRSA infection, accelerated the healing process, and promoted epithelial regeneration.

一个多世纪以来，碘在对抗细菌方面取得了成功，但它对人体皮肤组织和细胞的毒性作用一直被忽视。在这项工作中，基于牛粪生物炭的聚乙烯醇/聚乙烯吡咯烷酮水凝胶 (BCPP) 被设计为按需原位生产碘，并通过感染伤口治疗的光触发策略调节碘的释放。受益于活性氧 (ROS) 的产生和牛粪生物炭 (BC) 的光热转化特性，原位制备的水凝胶在可见光 (Vis) 光照射下将碘化物转化为活性碘，并在近红外 (NIR) 光照射下调节活性碘的释放。活性碘结合 BCPP 的光动力和光热效应赋予水凝胶对氨苄青霉素耐药大肠杆菌(AREC) 和甲氧西林耐药金黄色葡萄球菌(MRSA) 优异的抗菌作用，同时对哺乳动物细胞显示出低毒性。体内伤口治疗试验结果表明，该水凝胶可抵抗MRSA感染，加速愈合过程，促进上皮再生。