Single NIR laser-activated synergistic low-temperature photothermal therapy and self-oxygenated photodynamic therapy nano-platforms for bacteria infection

Abstract

The emergence and spread of drug-resistant bacterias with new resistance mechanisms leads to antimicrobial resistance and continues to threaten our ability to treat common infections. Herein, a nano-platform (PB@MnO2@MB@HA) was provided to bring significant bacterial inhibition via win-win photo-combination therapy strategy mediated by a single wavelength. More importantly, with well photothermal conversion efficiency, the nano-platform enables effective low temperature photothermal therapy (below 42 °C), where the heat generated is advantageous for the advancement of photodynamic therapy. Moreover, the addition of manganese dioxide promotes the supply of oxygen and addresses the limitations of low-oxygen environments on photodynamic therapy, further enhancing its therapeutic effect, which in turn compensates for the efficacy of low temperature photothermal. The nano-platform can effectively inhibit the growth of Gram-negative bacteria with an inhibition rate of 99%. In summary, the combined therapy of low-temperature photothermal therapy and self-oxygenated photodynamic therapy synergistically improves the efficacy of bacteria treatment while reducing the side effects associated with two therapy alone. The photo-combination nano-platform triggered by single wavelength near infrared irradiation has significant clinical application potential in overcoming the limitations of monotherapy for bacterial infection.