NIR enhanced nanozyme and synergy with ineffective antibiotic activities of BSA-Ag2Te for MRSA eradication.

With the prevalence of antibiotic-resistant bacteria (ARB), the antibacterial strategy based on combining multiple antibacterial pathways in one agent provides a promising way to combat ARB infections. Here, we reported that bovine serum albumin (BSA)-Ag2Te nanoparticles (NPs) could partially recover the antibacterial activity of ineffective β-lactam antibiotic cefotaxime (CTX) against methicillin-resistant Staphylococcus aureus (MRSA) by inhibiting β-lactamase and increasing membrane permeability of MRSA. The lower fractional inhibitory concentration index (0.187) and the combination index (≤ 0.68 ) provided the higher synergistic bactericidal activity of BSA-Ag2Te and CTX. Furthermore, BSA-Ag2Te NPs exhibited high near-infrared (NIR)-induced photothermal conversion and NIR-enhanced peroxidase-mimicking activities. Both the hyperthermia produced by NIR irradiation and ·OH generated through catalyzing H2O2 significantly enhanced the synergistic antibacterial activity of BSA-Ag2Te with CTX against MRSA. Over a short irradiation time (10 min), BSA-Ag2Te + CTX + H2O2 + NIR decreased 3.8 log10 of MRSA, which is higher than that of BSA-Ag2Te + CTX + NIR (2.8 log10) or BSA-Ag2Te + CTX + H2O2 (1.4 log10). Such a multiple-mode antibacterial platform based on BSA-Ag2Te NPs and ineffective CTX may provide an effective strategy to overcome refractory MRSA infections.