title: Preparation and Antibacterial Mechanism Insight of Polypeptide-Based Micelles with Excellent Antibacterial Activities.
abstract: Traditional antibiotics usually sterilize in chemical ways, which may lead to serious drug resistance. By contrast, peptide-based antibacterial materials are less susceptible to drug resistance. Herein we report the preparation of an antibacterial peptide-based copolymer micelle and the investigation of its membrane-penetration antibacterial mechanism by transmission electron microscopy (TEM). The copolymer is poly(l-lactide)-block-poly(phenylalanine-stat-lysine) [PLLA31-b-poly(Phe24-stat-Lys36)], which is synthesized by ring-opening polymerization. The PLLA chains form the core, whereas the polypeptide chains form the coronas of the micelle in aqueous solution. This micelle boasts excellent antibacterial efficacy against both Gram-positive and Gram-negative bacteria. Furthermore, TEM studies clearly reveal that the micelles pierce and then destroy the cell membrane of the bacteria. We also compared the advantages and disadvantages of two general methods for measuring the Minimal Inhibitory Concentration (MIC) values of antibacterial micelles. Overall, this study provides us with direct evidence for the antibacterial mechanism of polypeptide-based micelles and a strategy for synthesizing biodegradable antibacterial nanomaterials without antibiotic resistance.
authors.affiliation: Shanghai Tenth People's Hospital, Tongji University School of Medicine , 301 Middle Yanchang Road, Shanghai 200072, China.|Department of Polymeric Materials, School of Materials Science and Engineering, Tongji University , 4800 Caoan Road, Shanghai 201804, China.
authors.forename: Yuejing
authors.initials: Y
authors.lastname: Xi
authors.affiliation: Department of Polymeric Materials, School of Materials Science and Engineering, Tongji University , 4800 Caoan Road, Shanghai 201804, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Song
authors.affiliation: Department of Polymeric Materials, School of Materials Science and Engineering, Tongji University , 4800 Caoan Road, Shanghai 201804, China.
authors.forename: Songyao
authors.initials: S
authors.lastname: Tang
authors.affiliation: Department of Polymeric Materials, School of Materials Science and Engineering, Tongji University , 4800 Caoan Road, Shanghai 201804, China.
authors.forename: Nuosha
authors.initials: N
authors.lastname: Wang
authors.affiliation: Shanghai Tenth People's Hospital, Tongji University School of Medicine , 301 Middle Yanchang Road, Shanghai 200072, China.|Department of Polymeric Materials, School of Materials Science and Engineering, Tongji University , 4800 Caoan Road, Shanghai 201804, China.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Du
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001672:Biocompatible Materials / Q000737:chemistry*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D008099:Liver / Q000166:cytology / Q000187:drug effects*; D008823:Micelles; D049329:Nanostructures / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D008823:Micelles; D010455:Peptides; D011108:Polymers