Phenylboronic acid-functionalized BSA@CuS@PpIX nanoparticles for enhanced antibacterial photodynamic/photothermal therapy

To avoid the occurrence of antibiotic resistance and improve bactericidal effect, a multifunctional antibacterial nanoagent BCPP was successfully constructed for targeted photodynamic/photothermal combination therapy (PDT/PTT). The prepared BCPP consists of protoporphyrin (PpIX) as the photosensitizer, CuS nanoparticles as the photothermal agent, phenylboric acid (PBA) as the bacteria-targeting segment and bovine serum albumin (BSA) as the colloid stabilizer. Afterwards, its photodynamic/photothermal capacities, bacteria-targeting effect and bactericidal efficiency were intensively investigated. Experimental results confirmed its good singlet oxygen generation ability and high photothermal conversion efficiency. In addition, BCPP displayed good bacteria-targeting properties for both S. aureus and E. coli. Moreover, in vitro antibacterial assays proved its enhanced therapeutic efficiency through combined antibacterial PDT/PTT owing to PBA-mediated bacteria-targeting function. Finally, in vitro assays revealed its good hemocompatibility and low cytotoxicity. To sum up, our study offered a convenient method to build non-antibiotic antibacterial nanoagents for targeted PDT/PTT, and the prepared bactericidal is a promising drug candidate suitable for clinical trials in the future.