Synergistic antibacterial strategy based on photodynamic therapy: Progress and perspectives

The dramatic increase in drug resistant bacteria resistance to existing conventional antibiotics poses a great challenge to the effective treatment of infectious diseases. Photodynamic therapy (PDT) is receiving extensive attention as an antimicrobial strategy that is not to trigger bacterial resistance, but antibacterial PDT (APDT) has limitations such as weak penetration, easy dislodgement of nanoparticles, and short release distance and lifetime of reactive oxygen species (ROS). To address these problems, PDT antibacterial synergistic strategy enhances its antibacterial effectiveness and application scope. In this review,the antimicrobial synergy of PDT with antibiotics, antimicrobial agents, chemotherapy, photothermal therapy (PTT), and NO therapy was used to overcome the defects of single-treatment methods and achieve efficient antimicrobial efficacy. Photodynamic antibacterial synergistic strategy based on nanomaterials is introduced in detail in relation to the ability of lethal bacteria. Nanoparticle-mediated nanoplatforms can effectively accumulate at the site of infection to achieve multifunctional synergistic antimicrobial efficacy. Moreover the nanomaterial-based PDT/PTT antibacterial multiple synergistic strategy with appropriately elevated temperature reduces cellular activity and increases cell sensitivity to ROS for easy inactivation. Nanocomposite fiberous membranes with nano pore size structure, high specific surface area and good void penetration, which can effectively inhibit the invasion of exogenous microorganisms. The composite nanofiber membrane with rechargeable antibacterial activity has cyclic antibacterial effect under light, even in dark conditions. Finally, we conclude with an outlook section to provide some insights into the future prospects of PDT synergistic antibacterial strategy, which will provide more avenues for the practical application of APDT in the future.