Bacitracin-Engineered BSA/ICG Nanocomplex with Enhanced Photothermal and Photodynamic Antibacterial Activity.

To reduce the drug resistance of bacteria and enhance the antibacterial ability in bacterial infection therapy, we designed a new antibacterial nanoagent. In this system, a photosensitizer (indocyanine green, ICG) was loaded in bovine serum albumin (BSA) through hydrophobic-interaction-induced self-assembly to form stable BSA@ICG nanoparticles. Furthermore, a positively charged antibacterial peptide bacitracin (Bac) was physically immobilized onto the surface of BSA@ICG to generate a bacterial-targeted nanomedicine BSA@ICG@Bac through electrostatic interactions. Afterward, its photodynamic and photothermal activities were intensely evaluated. Moreover, its bactericidal efficiency was assessed antibacterial assays and bacterial biofilm destruction tests. First, the obtained BSA@ICG@Bac showed both good singlet oxygen generation property and high photothermal conversion efficiency. In addition, it showed enhanced photodynamic and photothermal antibacterial capacities and biofilm-removing ability due to Bac modification. To sum up, our research provided an economic and less-time-consuming approach to preparing antibacterial nanomedicines with excellent antibacterial ability. Therefore, the prepared antibacterial nanomedicines have great potential to be utilized in clinical trials in the future.