Biofilm-associated infections remain a tremendous obstacle to the treatment of microbial infections globally. However, the poor penetrability to a dense extracellular polymeric substance matrix of traditional antibacterial agents limits their antibiofilm activity. Here, we show that nanoaggregates formed by self-assembly of amphiphilic borneol-guanidine-based cationic polymers (BGNx-n) possess strong antibacterial activity and can eliminate mature Staphylococcus aureus (S. aureus) biofilms. The introduction of the guanidine moiety improves the hydrophilicity and membrane penetrability of BGNx-n. The self-assembled nanoaggregates with highly localized positive charges are expected to enhance their interaction with negatively charged bacteria and biofilms. Furthermore, nanoaggregates dissociate on the surface of biofilms into smaller BGNx-n polymers, which enhances their ability to penetrate biofilms. BGNx-n nanoaggregates that exhibit superior antibacterial activity have the minimum inhibitory concentration (MIC) of 62.5 μg·mL^–1 against S. aureus and eradicate mature biofilms at 4 × MIC with negligible hemolysis. Taken together, this size-variable self-assembly system offers a promising strategy for the development of effective antibiofilm agents.

中文翻译：

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自组装冰片-胍基两亲聚合物作为有效的抗生物膜剂


生物膜相关感染仍然是全球微生物感染治疗的巨大障碍。然而，传统抗菌剂对致密胞外聚合物基质的渗透性较差，限制了其抗生物膜活性。在这里，我们表明，由两亲性冰片-胍基阳离子聚合物（BGNx-n）自组装形成的纳米聚集体具有很强的抗菌活性，可以消除成熟的金黄色葡萄球菌（S. aureus）生物膜。胍部分的引入提高了BGNx-n的亲水性和膜渗透性。具有高度局部正电荷的自组装纳米聚集体有望增强其与带负电的细菌和生物膜的相互作用。此外，纳米聚集体在生物膜表面解离成更小的 BGNx-n 聚合物，这增强了它们穿透生物膜的能力。 BGNx-n 纳米聚集体表现出优异的抗菌活性，对金黄色葡萄球菌的最低抑菌浓度 (MIC) 为 62.5 μg·mL ^–1 ，并在 4 × MIC 时根除成熟生物膜，溶血可忽略不计。总而言之，这种尺寸可变的自组装系统为开发有效的抗生物膜剂提供了一种有前景的策略。