Nanomaterials-based photothermal therapy and its potentials in antibacterial treatment

With the prevalence of antibiotic-resistant bacteria, novel antibacterial strategies are urgently needed. In recent years, several antibiotics-independent physical approaches have attracted high attention and interests. Among those approaches, photothermal therapy (PTT), a novel non-invasive therapeutic technique, has exhibited great potentials in dealing with drug-resistant bacteria and bacterial biofilms. Photothermal agents (PTAs), which are either nanomaterials themselves or small molecules loaded in nanoparticles, are the essential element for PTT. How to deliver PTAs in a controlled manner is of great importance for high-efficiency and low-toxicity PTT. Therefore, a comprehensive understanding of various PTAs is required for the better application of PTT in antibacterial treatment. Herein, the physicochemical properties and antibacterial PTT of five types of PTAs are summarized. In addition, the PTT-involved multifunctional theranostics nanoplatforms and the potential approaches for reducing the side effects of PTT (such as targeted delivery and controlled release of PTAs) are also discussed.