Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, College of Food Engineering and Nutritional Science and ‡Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University , Xi'an 710119, China.
Langmuir. 2018 Jan 30;34(4):1574-1580. doi: 10.1021/acs.langmuir.7b03556. Epub 2018 Jan 18.
Polyethylenimine (PEI) has antimicrobial activity against Gram-positive (Staphylococcus aureus, S. aureus) and Gram-negative (Escherichia coli, E. coli), bacteria but is highly cytotoxic, and the selective antimicrobial activity against S. aureus is obviously better than that against E. coli. To reduce the cytotoxicity and improve the antibacterial activity against E. coli, we modified PEI with d-mannose through nucleophilic addition between primary amine and aldehyde groups to get mannose-modified polyethylenimine copolymer particles (Man-PEI CPs). The use of mannose may provide good targeting ability toward E. coli pili. The antibacterial activity of Man-PEI CPs was investigated. Man-PEI CPs shows specific and very strong killing capability against E. coli at a concentration of 10 μg/mL, which is the highest antimicrobial efficiency compared to that of unmodified PEI (220 μg/mL). The antibacterial mechanism demonstrated that the enhancement in antibacterial activity is due to specific recognition of the mannose and destroying the cell wall of the bacteria by PEIs. Importantly, the Man-PEI CPs show less cytotoxicity and excellent biocompatibility. The results indicate that Man-PEI CPs have great potential as novel antimicrobial materials to prevent bacterial infections and provide specific applications for killing E. coli.
聚乙烯亚胺（PEI）对革兰氏阳性（金黄色葡萄球菌，金黄色葡萄球菌）和革兰氏阴性（大肠杆菌，大肠杆菌）细菌具有抗菌活性，但具有高度细胞毒性，对金黄色葡萄球菌的选择性抗菌活性明显优于大肠杆菌。为了降低细胞毒性并提高对大肠杆菌的抗菌活性，我们通过伯胺和醛基之间的亲核加成将 PEI 与 D-甘露糖修饰，得到甘露糖修饰的聚乙烯亚胺共聚物颗粒（Man-PEI CPs）。甘露糖的使用可能为大肠杆菌菌毛提供良好的靶向能力。研究了 Man-PEI CPs 的抗菌活性。在 10 μg/mL 的浓度下，Man-PEI CPs 对大肠杆菌表现出特异性和非常强的杀伤能力，这是与未修饰的 PEI（220 μg/mL）相比抗菌效率最高的。抗菌机制表明，抗菌活性的增强是由于甘露糖的特异性识别以及 PEIs 破坏细菌细胞壁。重要的是，Man-PEI CPs 的细胞毒性较小，生物相容性良好。结果表明，Man-PEI CPs 作为预防细菌感染的新型抗菌材料具有很大的潜力，并为杀死大肠杆菌提供了特定的应用。
