title: Prolonged antibacterial effect of silver nanocomposites with different structures.
abstract: This study describes the synthesis of silver nanocomposites (Ag NCs), with different structures, decorated with silica nanoparticles (SiO2 NPs) and their antibacterial activity was evaluated. The core-shell microspheres were fabricated by the deposition of polydopamine (PDA) formed by the spontaneous oxidative polymerization of dopamine. Simultaneously, Ag(+) ions were reduced to nanosilver and subsequently deposited on the surface of the SiO2/PDA spheres to form SiO2/PDA/Ag NPs. Moreover, nanosilver encapsulated in mesoporous SiO2 NPs (Ag-MSN) were investigated for bactericidal activity to facilitate comparisons. Bacterial growth curves and reactive oxygen species (ROS) assays indicated that both Ag-MSN and SiO2/PDA/Ag NPs exhibited antimicrobial activity; however, at different stages, due to their distinct structures. This study revealed that the production of ROS and damage to the membrane were the two major mechanisms of the bactericidal activity of Ag NCs. The antibacterial mechanisms for each NC are discussed and supported by observations from transmission electron microscopy.
authors: College of Marine Science and Engineering, Shanghai Maritime University, Shanghai 201306, China. Electronic address: liutao@shmtu.edu.cn.
authors: Tao
authors: T
authors: Liu
authors: College of Marine Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
authors: Xiao
authors: X
authors: Song
authors: College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors: Zhangwei
authors: Z
authors: Guo
authors: College of Marine Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
authors: Yaohua
authors: Y
authors: Dong
authors: College of Marine Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
authors: Na
authors: N
authors: Guo
authors: College of Marine Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
authors: Xueting
authors: X
authors: Chang
mesh_terms: D000900:Anti-Bacterial Agents; D004305:Dose-Response Relationship, Drug; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D053761:Nanocomposites / Q000737:chemistry*; D010316:Particle Size; D017382:Reactive Oxygen Species / Q000378:metabolism; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013499:Surface Properties; D014733:Vibrio / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D017382:Reactive Oxygen Species; D012834:Silver
keywords: Antibacterial; Nanocomposites; Polydopamine; Silver; Structures