title: Fabrication of cross-linked polyethyleneimine microfibers by reactive electrospinning with in situ photo-cross-linking by UV radiation.
abstract: The objective of this work is to demonstrate the feasibility of fabrication of cross-linked polyethyleneimine microfibers by a reactive photo-electrospinning technology. Linear polyethyleneimine (L-PEI) has been grafted with cross-linkable methacrylate moiety by reaction with glycidyl methacrylate (GMA), enabling the polymer to cross-link upon UV exposure. The photo-cross-linking reaction was characterized by a photo-rheometer. Neat L-PEI or methacrylated L-PEI tends to aggregate rendering it very difficult to electrospin into microfibers. A high molecular weight polyvinylpyrrolidone (PVP) is an efficient chain entanglement enhancer for both L-PEI and methacrylated L-PEI and helpful to maintain fibrous structure. An optimized composition consisted of 10% methacrylated L-PEI (less than 14.8% methacrylation of total L-PEI) combined with 2% PVP and 1% photoinitiator in ethanol was successfully electrospun into smooth cross-linked microfibers using the reactive electrospinning device. Diameters of cross-linked fibers can be controlled from 419 nm to 2 μm depending on methacrylation degree and UV irradiation intensity. The resultant cross-linked L-PEI microfibers have demonstrated significantly improved solvent resistance, thermal stability, and mechanical properties. The distinguished characteristics of this novel reactive electrospinning technology are the high cross-linking efficiency and minimal toxic chemical residues in the products. The stability of the fibers can be readily modified and controlled by the cross-linking degree, which is of great importance for biomedical applications.
authors.affiliation: Department of Comprehensive Dentistry and Biomaterials, Health Science Center, Louisiana State University, 1100 Florida Avenue, Box 137, New Orleans, Louisiana 70119, USA. xxu@lsuhsc.edu
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Xu
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Zhang
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Fan
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D004563:Electrochemistry; D004852:Epoxy Compounds / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry; D011094:Polyethyleneimine / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D004852:Epoxy Compounds; D008689:Methacrylates; D011108:Polymers; D011094:Polyethyleneimine; D011205:Povidone; C007870:glycidyl methacrylate