NIR-enhanced nanoreactors within Cu2O@Au–Pt scaffold for antibacterial therapy of diabetic wounds

Diabetic patients frequently suffer from skin ulcers exacerbated by bacterial infections. Cu 2 O nanozymes present a promising antibacterial alternative to antibiotics due to their enzyme-like catalytic activity. However, their efficacy is hindered by the low H 2 O 2 concentration in the bacterial microenvironment and the slow electron transfer during catalysis. To mitigate these limitations, we exploited Cu 2 O's intrinsic reducing ability to grow Au–Pt nanoparticles, thereby creating Cu 2 O@Au–Pt nanoreactors. Subsequently, we fabricated Cu 2 O@Au–Pt/Polycaprolactone skin scaffolds using laser powder bed fusion. In the scaffold, Cu 2 O catalyzed H 2 O 2 to produce hydroxyl radicals, inducing bacterial apoptosis. Au–Pt nanoparticles enhanced this catalysis in three manners: by providing additional H 2 O 2 through glucose oxidation, elevating the reaction temperature via plasmonic resonance, and facilitating electron transfer through metal-support interactions. Photothermal experiments and simulations illuminated the near-field coupling and interface hotspot formation mechanisms in the Cu 2 O@Au–Pt hybrid structure, boosting the catalytic rate at the interface. DFT calculations and electrochemical tests verified a reduced energy barrier for electron transfer in the Cu 2 O@Au–Pt system, enhancing its redox capability. Upon NIR irradiation, the scaffold increased intracellular ROS by 84.5 % and achieved a 99.9 % antibacterial efficacy against E. coli. These findings highlight the potential of the Cu 2 O@Au–Pt nanozyme scaffold for treating diabetic wounds.