The increasing incidence of drug-resistant strains of bacteria necessitates the development of new classes of antimicrobials. Host defense peptides, also known as antimicrobial peptides, are promising in this regard but have several drawbacks. Herein, we show that peptidomimetic polyurethanes with pendant functional groups that mimic lysine and valine amino acid residues have high antibacterial activity against Gram negative Escherichia coli, yet are less effective against Gram positive Staphylococcus aureus. All the polyurethanes designed in this study display high bactericidal activity against E. coli, whereas the polyurethanes with high concentrations of lysine mimicking functional groups display minimal cytotoxicity toward mammalian cells. Control experiments with pexiganan, an analogue of the host defense peptide magainin, showed that the polyurethanes described here have high bactericidal activity, while having comparable hemocompatibility and lower mammalian cell toxicity. Overall, the results point to an encouraging new class of peptidomimetic synthetic polymers with selective bactericidal activity to E. coli and low mammalian cell toxicity.

中文翻译：

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对大肠杆菌具有显着选择性的杀菌拟肽聚氨酯

细菌耐药菌株的发病率不断增加，因此有必要开发新型的抗菌剂。宿主防御肽，也称为抗微生物肽，在这方面是有前途的，但有一些缺点。本文中，我们显示具有模拟赖氨酸和缬氨酸氨基酸残基的侧基官能团的拟肽聚氨酯对革兰氏阴性大肠杆菌具有较高的抗菌活性，但对革兰氏阳性金黄色葡萄球菌的抗菌作用较小。本研究中设计的所有聚氨酯均显示出对大肠杆菌的高杀菌活性，而具有高浓度赖氨酸模拟功能基团的聚氨酯则对哺乳动物细胞显示出最小的细胞毒性。用pexiganan（一种宿主防御肽magainin的类似物）进行的对照实验表明，此处所述的聚氨酯具有较高的杀菌活性，同时具有相当的血液相容性和较低的哺乳动物细胞毒性。总体而言，结果表明，令人鼓舞的新型拟肽合成聚合物具有对大肠杆菌的选择性杀菌活性和低哺乳动物细胞毒性。