Fe-doped polyoxometalates nanoclusters for near-infrared mild-temperature photothermal bacterial disinfection: A biomechanical perspective
Abstract
Currently, multidrug-resistant (MDR) pathogens are becoming a human and economic burden worldwide and have posed a grave threat to public health. In this case, mild-temperature photothermal therapy (PTT) has become a promising alternative to conventional antibiotics because it has the characteristics of minimally invasive property, targeted destructiveness, and low toxicity. To realize effective photothermal therapy, it is imperative to fabricate multifunctional photothermal formulations with better performance. In this study, novel Fe-doped polyoxometalate (Fe-POM) nanoclusters were successfully prepared by the one-pot method. Due to the strong absorption efficiency in the near-infrared (NIR) region, high photothermal conversion efficiency, and photothermal cycling stability, Fe-POM nanoclusters are sufficient to be used as an efficient photothermal agent for highly effective mild-temperature photothermal therapy. From a biomechanical perspective, the Fe-POM nanoclusters not only generate heat under NIR irradiation but also produce hydroxyl radicals (·OH) through the redox cycling of Fe2+/Fe3+ and Mo5+/Mo6+ pairs. The reactive oxygen species (ROS) generated disrupt bacterial cell membranes and alter their biomechanical properties, such as membrane stiffness and permeability, rendering the bacteria more susceptible to mild-temperature PTT. The synergistic effect of ROS-induced biomechanical stress and photothermal heating significantly enhances bacterial disinfection. Antibacterial experiments demonstrated that Fe-POM nanoclusters, under PTT conditions, effectively induce bacterial death while maintaining good biocompatibility. This study highlights the potential of Fe-POM nanoclusters as a multifunctional photothermal agent for combating bacterial infections. This work not only advances the field of photothermal therapy but also provides a novel strategy for treating bacteria-associated diseases through biomechanical modulation.
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