Designing of membrane-active nano-antimicrobials based on cationic copolymer functionalized nanodiamond: Influence of hydrophilic segment on antimicrobial activity and selectivity

Publication date: 1 November 2018Source: Materials Science and Engineering: C, Volume 92Author(s): Weiwei Cao, Xi Wang, Qiang Li, Xuefeng Peng, Lina Wang, Peili Li, Zhiwen Ye, Xiaodong XingAbstractDesigning cationic nano-antimicrobial is a promising solution for combating drug resistant microbes. In this work, hydrophilic cationic copolymer was applied for the surface functionalization of nanodiamonds (NDs) aiming at developing a highly membrane-active nano-antibacterial agent with satisfactory selectivity. As a result, after functionalization, the increased repulsive forces within NDs and interaction with solvent molecular network made the heavily aggregated pristine NDs break down into tiny nanoparticles with particle size ranging from 10 to 100 nm. The improved hydrophilicity and enlarged surface area endowed QND-H5 and QND-H10 a powerful bactericidal capability toward both of Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). In the further bactericidal assessment, it was also demonstrated that the formation of hydrogen bonding between the 2-hydroxyethyl methacrylate (HEMA) side chains and lipid head groups of bacterial membrane also contributed to the enhanced bactericidal ability. Field emission scanning electron microscopy analysis confirmed that as-prepared nano-hybrid acted bactericidal ability via physical nature of outer membrane and cytoplasmic membrane-separating destruction mechanism toward E. coli, which may derive f...
Source: Materials Science and Engineering: C - Category: Materials Science Source Type: research