Active iodine regulated in cow dung biochar-based hydrogel combined with PDT/PTT for MRSA infected wound therapy
Qinggele Borjihan, Suriguga Meng, Haoran Bai, Ting Chen, Xinshang Hu, Douxin Xiao, Shi Lan, Alideertu Dong
Abstract
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.