title: Effects of quaternization on the morphological stability and antibacterial activity of electrospun poly(DMAEMA-co-AMA) nanofibers.
abstract: Electrospun nanofibers with antibacterial activity are greatly promising for medical treatment and water purification. Herein we report antibacterial nanofibers electrospun from a series of poly(dimethylamino ethyl methacrylate-co-alkyl methacrylates) (poly(DMAEMA-co-AMA)) and to distinguish the effects of free and cross-linked cations derived from quanternization on the antibacterial activity. Poly(DMAEMA-co-AMA)s are simply synthesized by free radical polymerization from commercial monomers. DSC analysis indicates that they have Tg lower than room temperature and thus the electrospun nanofibers adhere to each other and evenly tend to form films, instead of keeping cylinderic shape. Benzyl chloride (BC) and p-xylylene dichloride (XDC) can quaternize DMAEMA units and to generate cations on the nanofiber surface. XPS analysis and colorimetric assay determine the quaternization degree and the surface accessible quaternary amines (N(+)), respectively. It is very promising that this quaternization endows the electrospun nanofibers with both stable morphology and antibacterial activity. The BC-quaternized fibers show better antibacterial behavior against Escherichia coli and Staphylococcus aureus than those of the XDC-quaternized/cross-linked ones, because cross-linking suppresses the chain mobility of cations. Our results confirm that antibacterial nanofibers can be facilely prepared and chain mobility of the formed cations is the necessary prerequisite for their antibacterial activity.
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, 310027 Hangzhou, China; Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou 310009, China.
authors.forename: Jing-Wei
authors.initials: JW
authors.lastname: Xu
authors.affiliation: Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou 310009, China. Electronic address: wangyao@zju.edu.cn.
authors.forename: Yao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, 310027 Hangzhou, China.
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Yang
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, 310027 Hangzhou, China.
authors.forename: Xiang-Yu
authors.initials: XY
authors.lastname: Ye
authors.affiliation: Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou 310009, China. Electronic address: xlren@zju.edu.cn.
authors.forename: Ke
authors.initials: K
authors.lastname: Yao
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, 310027 Hangzhou, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ji
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, 310027 Hangzhou, China. Electronic address: xuzk@zju.edu.cn.
authors.forename: Zhi-Kang
authors.initials: ZK
authors.lastname: Xu
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000627:therapeutic use*; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D057139:Nanofibers; D009757:Nylons / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000900:Anti-Bacterial Agents; D008689:Methacrylates; D009757:Nylons; C109846:poly(2-(diethylamino)ethyl methacrylate)
keywords: Antibacterial activity; Chain mobility; Electrospinning; Electrospun nanofibers; Quaternization