title: Preparation of size-controlled silver nanoparticles and chitosan-based composites and their anti-microbial activities.
abstract: We previously reported a simple method for the preparation of size-controlled spherical silver nanoparticles (Ag NPs) generated by autoclaving a mixture of silver-containing glass powder and glucose. The particle size is regulated by the glucose concentration, with concentrations of 0.25, 1.0 and 4.0 wt% glucose providing small (3.48 ± 1.83 nm in diameter), medium (6.53 ± 1.78 nm) and large (12.9 ± 2.5 nm) particles, respectively. In this study, Ag NP/chitosan composites were synthesized by mixing each of these three Ag NP suspensions with a 75% deacetylated (DAc) chitosan suspension (pH 5.0) at room temperature. The Ag NPs were homogeneously dispersed and stably embedded in the chitosan matrices. The Ag NP/chitosan composites were obtained as yellow or brown flocs. It was estimated that approximately 60, 120 and 360 μg of the small, medium and large Ag NPs, respectively, were maximally embedded in 1 mg of chitosan. The bactericidal and anti-fungal activities of the Ag NP/chitosan composites increased as the amount of Ag NPs in the chitosan matrix increased. Furthermore, smaller Ag NPs (per weight) in the chitosan composites provided higher bactericidal and anti-fungal activities.
authors.affiliation: Faculty of System Design, Tokyo Metropolitan University, Tokyo, Japan Research Institute, National Defense Medical College, Saitama, Japan.
authors.forename: Vinh Quang
authors.initials: VQ
authors.lastname: Nguyen
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ishihara
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Mori
authors.forename: Shingo
authors.initials: S
authors.lastname: Nakamura
authors.forename: Satoko
authors.initials: S
authors.lastname: Kishimoto
authors.forename: Masanori
authors.initials: M
authors.lastname: Fujita
authors.forename: Hidemi
authors.initials: H
authors.lastname: Hattori
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kanatani
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ono
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyahira
authors.forename: Takemi
authors.initials: T
authors.lastname: Matsui
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D000935:Antifungal Agents / Q000737:chemistry* / Q000494:pharmacology; D001228:Aspergillosis / Q000188:drug therapy; D001234:Aspergillus niger / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D004927:Escherichia coli Infections / Q000188:drug therapy; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D012834:Silver; D048271:Chitosan
keywords: Silver-nanoparticles; anti-fungal; bactericidal; chitosan; composites