The persistence of multidrug resistance among microorganisms has directed a mandate towards a hunt for the development of alternative therapeutic modalities. In this context, antimicrobial photodynamic therapy (aPDT) is sprouted as a novel strategy to mitigate biofilms and planktonic cells of pathogens. Nanoparticles (NPs) are reported with unique intrinsic and antimicrobial properties. Therefore, silver NPs (AgNPs) were investigated in this study to determine their ability to potentiate the aPDT of photosensitizer against Staphylococcus aureus and Pseudomonas aeruginosa. Biologically synthesized AgNPs were surface coated with methylene blue (MB) and studied for their aPDT against planktonic cells and biofilms of bacteria. The nano-conjugates (MB-AgNPs) were characterized for their size, shape and coated materials. MB-AgNPs showed significant phototoxicity against both forms of test bacteria and no toxicity was observed in the dark. Moreover, activity of MB-AgNPs was comparatively higher than that of the free MB, which concludes that MB-AgNPs could be an excellent alternative to combat antibiotic resistant bacteria.

中文翻译：

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亚甲蓝修饰的生物银纳米颗粒增强了铜绿假单胞菌和金黄色葡萄球菌的光动力失活。

微生物之间对多药耐药性的持续存在已促使人们寻求开发其他治疗方法。在这种情况下，抗菌光动力疗法（aPDT）作为缓解病原体生物膜和浮游细胞的新策略而萌芽。据报道，纳米粒子（NPs）具有独特的内在和抗菌特性。因此，本研究对银纳米粒（AgNP）进行了研究，以确定其增强光敏剂对金黄色葡萄球菌和铜绿假单胞菌的aPDT的能力。。生物合成的AgNPs表面涂有亚甲蓝（MB），并研究了其对浮游细胞和细菌生物膜的aPDT。纳米共轭物（MB-AgNPs）的大小，形状和涂层材料进行了表征。MB-AgNP对两种形式的测试细菌均表现出明显的光毒性，在黑暗中未观察到毒性。此外，MB-AgNPs的活性相对高于游离MB，这表明MB-AgNPs可能是抵抗抗生素耐药细菌的绝佳替代品。