Photothermal therapy for bacteria-infected wound healing <i>via</i> a cation–anion inverted antiperovskite with full-spectrum solar absorption

Clinical treatment of open wounds is challenging due to bacterial infection and biofilm protection. Antibiotics are commonly utilized as antibacterials; however, multidrug resistance (MDR) severely affects the therapeutic effect. Therefore, developing a non-antibiotic strategy for treating infections and accelerating wound healing is highly required. Herein, for the first time, an electronically inverted antiperovskite, InNNi₃, has been demonstrated as a novel photothermal material with efficient and broad-spectrum anti-bacterial activity. Due to the quasi-continuous energy levels and inverse coordination with cations/anions exchanged in crystal sites, InNNi₃ possesses a near-unity photothermal conversion efficiency (96.9%) and a positively charged surface, which together contribute to the high antimicrobial activity (99.9%) <i>via</i> photothermal activation and electrostatic interaction with pathogens, including <i>methicillin-resistant Staphylococcus aureus</i> (<i>MRSA</i>), <i>Escherichia coli</i> (<i>E. coli</i>) and <i>Candida albicans</i> (<i>C. albicans</i>) within several minutes. Moreover, as an effective antibiofilm agent, InNNi₃ exhibits over 99% scavenging effect on biofilms. An accelerated healing rate for infected wounds has also been achieved using an InNNi₃-treatment strategy under NIR irradiation by reducing inflammation, promoting collagen deposition, boosting early expression of CD31 and facilitating the regeneration of dermis and skin appendages. The excellent biocompatibility of InNNi₃ further demonstrates its great potential for clinical applications in future.