title: Antibacterial action mode of quaternized carboxymethyl chitosan/poly(amidoamine) dendrimer core-shell nanoparticles against Escherichia coli correlated with molecular chain conformation.
abstract: The action mode of quaternized carboxymethyl chitosan/poly(amidoamine) dendrimer core-shell nanoparticles (CM-HTCC/PAMAM) against Escherichia coli (E. coli) was investigated via a combination of approaches including measurements of cell membrane integrity, outer membrane (OM) and inner membrane (IM) permeability, and scanning electron microscopy (SEM). CM-HTCC/PAMAM dendrimer nanoparticles likely acted in a sequent event-driven mechanism, beginning with the binding of positively charged groups from nanoparticle surface with negative cell surface, thereby causing the disorganization of cell membrane, and subsequent leakage of intracellular components which might ultimately lead to cell death. Moreover, the chain conformation of polymers was taken into account for a better understanding of the antibacterial action mode by means of viscosity and GPC measurements. High utilization ratio of positive charge and large specific surface area generated from a compacted conformation of CM-HTCC/PAMAM, significantly different from the extended conformation of HTCC, were proposed to be involved in the antibacterial action.
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; School of Science, Tianjin University of Commerce, Tianjin 300134, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wen
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China. Electronic address: yaofanglian@tju.edu.cn.
authors.forename: Fanglian
authors.initials: F
authors.lastname: Yao
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Sun
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300222, China.
authors.forename: Zhilei
authors.initials: Z
authors.lastname: Tan
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Tian
authors.affiliation: College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300222, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Xie
authors.affiliation: College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300222, China.
authors.forename: Qingchao
authors.initials: Q
authors.lastname: Song
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D048271:Chitosan / Q000031:analogs & derivatives / Q000737:chemistry; D050091:Dendrimers / Q000737:chemistry* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects*; D007425:Intracellular Membranes / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D010539:Permeability; D055672:Static Electricity; D014783:Viscosity
chemical_list: D000900:Anti-Bacterial Agents; D050091:Dendrimers; C104700:PAMAM Starburst; C514968:carboxymethyl-chitosan; D048271:Chitosan
keywords: Action mode; Antibacterial activity; Core–shell nanoparticles; Membrane integrity and permeability; Quaternized carboxymethyl chitosan/poly(amidoamine) dendrimer