Polydopamine-functionalized Selenium Nanoparticles as a Photoresponsive Synergistic Antibacterial Platform

Background: Bacterial infections have always been one of the medical challenges facing mankind. Compared with conventional antibiotic therapy, photoresponsive synergistic antibacterial offers a new therapeutic modality. Results Herein, a photoresponsive synergistic therapeutic antibacterial platform was designed and constructed by polydopamine-functionalized selenium nanoparticles as carrier loading indocyanine green (Se@PDA-ICG). The synergistic therapeutic platform was confirmed by characterization and the antibacterial activity of Se@PDA-ICG against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) was investigated. Se@PDA-ICG at a low concentration of 125 µg/mL in dark showed antibacterial rates of 14.3% and 52.7% against E. coli and S. aureus, respectively. Under 808 nm laser irradiation, the antibacterial rates against both bacteria increased to 100%. Furthermore, in the mouse wound infection model, the wound closure rate of the Se@PDA-ICG photoresponse group was 88.74% compared with the 45.8% of the control group after 8 days treatment, indicating that it could effectively kill bacteria and dramatically accelerate the wound healing process. Conclusions These results suggested that Se@PDA-ICG could be a promising photo-activated antibacterial candidate material for biomedical applications.