Photothermal Therapy with Ag Nanoparticles in Mesoporous Polydopamine for Enhanced Antibacterial Activity

Photothermal therapy (PTT) is a promising method to kill pathogenic bacteria. However, using single-modal PTT, it is easy to cause tissue damage because of the overtemperature. Hence, it is necessary to combine PTT with other antibacterial strategies. In this study, we employed silver nanoparticles (Ag NPs) and mesoporous polydopamine (MPDA) nanoparticles to establish a multimodal antibacterial platform (MPDA@Ag). MPDA nanoparticles not only served as a photothermal transduction agent to convert light-energy to heat under the irradiation of near-infrared (NIR) light but also acted as a reducer to reduce Ag NPs in situ. Because Ag NPs can effectively kill bacteria, MPDA@Ag can overcome the drawbacks of the single-modal PTT antibacterial strategy, achieving a synergistic antibacterial effect. Moreover, as an antibiotic-free strategy, MPDA@Ag was less likely to induce drug resistance when killing bacteria. In summary, this platform offered a simple and practical means to achieve excellent antibacterial activity and supplied a good alternative to fight pathogenic bacteria.