Clinical & Health Sciences, University of South Australia, Adelaide, SA 5095, Australia.
Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.
ACS Appl Mater Interfaces. 2022 Jan 12;14(1):390-403. doi: 10.1021/acsami.1c21657. Epub 2021 Dec 22.
Silver-based nano-antibiotics are rapidly developing as promising alternatives to conventional antibiotics. Ideally, to remain potent against a wide range of drug-resistant and anaerobic bacteria, silver-based nano-antibiotics should easily penetrate through the bacterial cell walls and actively release silver ions. In this study, highly monodispersed, ultrasmall (<3 nm), polycationic silver nanoclusters (pAgNCs) are designed and synthesized for the elimination of a range of common Gram-negative and Gram-positive pathogens and their corresponding established and matured biofilms, including those composed of multiple species. The pAgNCs also show greatly enhanced antibacterial efficacy against anaerobic bacteria such as and These results demonstrate that the cationic nature facilitates better penetration to the bacterial cell membrane while the presence of a high percentage (>50%) of silver ions (i.e., Ag nanoreservoirs) on the cluster surface maintains their efficiency in both aerobic and anaerobic conditions. Significantly, the pAgNCs showed a strong capacity to significantly delay the development of bacterial resistance when compared to similar-sized negatively charged silver nanoparticles or conventional antibiotics. This study demonstrates a novel design strategy that can lay the foundation for the development of future highly potent nano-antibiotics effective against a broad spectrum of pathogens and biofilms needed in many everyday life applications and industries.
基于银的纳米抗生素作为传统抗生素的替代品迅速发展。理想情况下，为了保持对广泛的耐药性和厌氧菌的有效作用，基于银的纳米抗生素应该容易穿透细菌细胞壁并主动释放银离子。在这项研究中，设计并合成了高度单分散的、超小的（<3nm）、带正电荷的银纳米团簇（pAgNCs），以消除一系列常见的革兰氏阴性和革兰氏阳性病原体及其相应的成熟生物膜，包括由多种物种组成的生物膜。pAgNCs 对厌氧菌如 和 也表现出大大增强的抗菌功效。这些结果表明，正电荷性质有助于更好地穿透细菌细胞膜，而簇表面存在高比例（>50%）的银离子（即 Ag 纳米储库）保持了它们在有氧和无氧条件下的效率。值得注意的是，与类似大小的带负电荷的银纳米粒子或传统抗生素相比，pAgNCs 具有显著延缓细菌耐药性发展的能力。这项研究展示了一种新的设计策略，可以为未来开发针对广泛的病原体和生物膜的高效纳米抗生素奠定基础，这些抗生素在许多日常生活应用和工业中都需要。
