Cu single-atom embedded g-C3N4 nanosheets rehabilitate multidrug-resistant bacteria infected diabetic wounds via photoswitchable cascade reaction

To tackle elevated blood glucose, multidrug-resistant (MDR) bacterial infections, and persistent inflammation in diabetic wounds, we present a therapeutic strategy that employs a photoswitch-controlled catalytic cascade reaction, utilizing a photocatalytic material engineered through the synergistic regulation of nitrogen vacancies and single-atom embedding. Under visible light illumination, the N vacancy exist in g-C3N4 (CN) significantly enhances photocatalytic glucose oxidation to regulate the hyperglycemia condition at diabetic wound sites, and the atomically dispersed Cu promotes the generation of •OH and •O2– to efficiently eliminate MDR bacteria ( > 99.9%). Under dark conditions, excess ROS are scavenged by Cu/CN, reducing inflammation of wounds and promoting polarization of M2 macrophages. Serum biochemical and vital organs histopathological analyses after 14 days of treatment confirm the biosafety profile of Cu/CN. This photoswitchable cascade reaction effectively treats MDR bacterial-infected diabetic wounds in male mice, highlighting its potential for antibiotic-free therapy with promising clinical translation applications.