title: Preparation and antibacterial activity of chitosan nanoparticles.
abstract: Chitosan nanoparticles, such as those prepared in this study, may exhibit potential antibacterial activity as their unique character. The purpose of this study was to evaluate the in vitro antibacterial activity of chitosan nanoparticles and copper-loaded nanoparticles against various microorganisms. Chitosan nanoparticles were prepared based on the ionic gelation of chitosan with tripolyphosphate anions. Copper ions were adsorbed onto the chitosan nanoparticles mainly by ion-exchange resins and surface chelation to form copper-loaded nanoparticles. The physicochemical properties of the nanoparticles were determined by size and zeta potential analysis, atomic force microscopy (AFM), FTIR analysis, and XRD pattern. The antibacterial activity of chitosan nanoparticles and copper-loaded nanoparticles against E. coli, S. choleraesuis, S. typhimurium, and S. aureus was evaluated by calculation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results show that chitosan nanoparticles and copper-loaded nanoparticles could inhibit the growth of various bacteria tested. Their MIC values were less than 0.25 microg/mL, and the MBC values of nanoparticles reached 1 microg/mL. AFM revealed that the exposure of S. choleraesuis to the chitosan nanoparticles led to the disruption of cell membranes and the leakage of cytoplasm.
authors.affiliation: Zhenjiang University, Animal Science College, Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Hangzhou 310029, China. lfqi@zju.edu.cn
authors.forename: Lifeng
authors.initials: L
authors.lastname: Qi
authors.forename: Zirong
authors.initials: Z
authors.lastname: Xu
authors.forename: Xia
authors.initials: X
authors.lastname: Jiang
authors.forename: Caihong
authors.initials: C
authors.lastname: Hu
authors.forename: Xiangfei
authors.initials: X
authors.lastname: Zou
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D048271:Chitosan / Q000737:chemistry / Q000494:pharmacology*; D003300:Copper; D004926:Escherichia coli / Q000187:drug effects; D005782:Gels; D008826:Microbial Sensitivity Tests; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D010316:Particle Size; D013210:Staphylococcus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D005782:Gels; D003300:Copper; D048271:Chitosan