State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China.
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering , Zhejiang University , Hangzhou 310027 , China.
ACS Appl Mater Interfaces. 2018 May 9;10(18):15395-15400. doi: 10.1021/acsami.8b01117. Epub 2018 Apr 24.
Methicillin-resistant Staphylococcus aureus (MRSA) has been one of the major nosocomial pathogens to cause frequent and serious infections that are associated with various biomedical surfaces. This study demonstrated that surface modified with host defense peptide-mimicking β-peptide polymer, has surprisingly high bactericidal activities against Escherichia coli ( E. coli) and MRSA. As surface-tethered β-peptide polymers cannot move freely to adopt the collaborative interactions with bacterial membrane and are too short to penetrate the cell envelop, we proposed a mode of action by diffusing away the cell membrane-stabilizing divalent ions, Ca and Mg. This hypothesis was supported by our study that Ca and Mg supplementation in the assay medium causes up to 80% loss of bacterial killing efficacy and that the addition of divalent ion chelating ethylenediaminetetraacetic acid into the above assay medium leads to significant recovery of the bacterial killing efficacy. In addition to its potent bacterial killing efficacy, the surface-tethered β-peptide polymer also demonstrated excellent biocompatibility by displaying no hemolysis and supporting mammalian cell adhesion and growth. In conclusion, this study demonstrated the potential of β-peptide polymer-modified surface in addressing nosocomial infections that are associated with various surfaces in biomedical applications.
耐甲氧西林金黄色葡萄球菌（MRSA）一直是引起频繁且严重感染的主要医院病原体之一，这些感染与各种生物医学表面有关。本研究表明，经过具有宿主防御肽模拟β-肽聚合物表面修饰后，对大肠杆菌（E. coli）和耐甲氧西林金黄色葡萄球菌（MRSA）具有惊人的高杀菌活性。由于固定在表面的β-肽聚合物不能自由移动以与细菌膜进行协同相互作用，并且太短而无法穿透细胞膜，因此我们提出了一种通过扩散稳定细胞膜的二价离子（Ca 和 Mg）的作用模式。我们的研究支持了这一假设，即在测定介质中补充 Ca 和 Mg 会导致高达 80%的杀菌效力丧失，并且向上述测定介质中添加二价离子螯合剂乙二胺四乙酸会导致杀菌效力显著恢复。除了具有强大的杀菌功效外，固定在表面的β-肽聚合物还通过显示无溶血作用和支持哺乳动物细胞黏附和生长而表现出优异的生物相容性。总之，本研究表明了β-肽聚合物修饰表面在解决与生物医学应用中各种表面相关的医院感染方面的潜力。
