Cu-S-Mo Interfacial Sites in CuO2@MoS2/PLLA Scaffolds for Robust Synergistic Antibacterial Efficacy via CDT and PTT

Abstract

Bacterial infections considerably limit the success of scaffold transplantation. CuO2 may generate hydroxyl radicals through a self-cascade catalytic process, which is effective for sterilization. However, reducing CuO2-derived Cu+ ions to Cu° can lead to a decline in catalytic activity. To overcome these limitations, we anchored CuO2 onto MoS2 to establish stable Cu-S-Mo interfacial sites. The CuO2/MoS2 nanozyme was fabricated using a low-temperature co-precipitation technique and introduced into poly-L-lactic acid scaffolds using selective laser sintering. The Cu-S-Mo interfacial sites showed a triad of functions that synergistically enhanced catalytic performance. These sites stabilized the Cu atoms, augmented catalytic activity by facilitating efficient electron transfer through the Mo4+/Mo6+ redox couple, and improved the conduction of heat derived from the photothermal response of MoS2 to the Cu catalyst. The synergistic action of chemodynamic and photothermal therapy, mediated by the Cu-S-Mo sites, resulted in remarkable antibacterial efficacy, with 92.3% and 93.5% inhibition rates against Staphylococcus aureus and Escherichia coli, respectively. Experimental evidence and simulations demonstrated that Cu-S-Mo structure stabilized the Cu atoms and improved electron transfer via interatomic charge transfer. These results highlight the potential of the CuO2@MoS2/PLLA scaffold in eliminating bacterial infections.