title: A linear-dendritic cationic vector for efficient DNA grasp and delivery.
abstract: This paper presents an attempt to design an efficient and biocompatible cationic gene vector via structural optimization that favors the efficient utilization of amine groups for DNA condensation. To this end, a linear-dendritic block copolymer of methoxyl-poly(ethylene glycol)-dendritic polyglycerol-graft-tris(2-aminoethyl)amine (mPEG-DPG-g-TAEA) was prepared with specially designed multiple functions including strong DNA affinity, endosomal buffering and expected serum-tolerance. Based on the transfection in serum-free and serum-conditioned media, the influences of the polymer structures including the degree of polymerization of DPG and TAEA substitution degree were explored. As compared to polyethylenimine (M(w)=5 kDa) (PEI5k) with similar molecular weight and higher amine density, mPEG-DPG-g-TAEA displayed comparably high DNA affinity due to the special linear-dendritic architecture. Consequently, at very low N/P ratio, mPEG-DPG-g-TAEA vectors could mediate efficient in vitro luciferase expression at levels that are comparable with or even superior to the commercially available Lipofectamine™ 2000, while being apparently higher than PEI5k. The designed vectors exhibit considerably higher cell biocompatibility and better resistance against bovine serum albumin adsorption than PEI5k. The stability of the complexes on coincubation with heparin was found to be largely dependent on the polymer structure. As concluded from the comparative transfection study in the absence/presence of chloroquine, it is likely that the polycation itself could produce endosomal buffering. This linear-dendritic vector shows promising potential for the application of gene delivery.
authors.affiliation: Key Laboratory of Biomedical Polymers (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.forename: Yun-xia
authors.initials: YX
authors.lastname: Sun
authors.forename: Wen-jie
authors.initials: WJ
authors.lastname: Yi
authors.forename: Juan
authors.initials: J
authors.lastname: Yang
authors.forename: Chen-wei
authors.initials: CW
authors.lastname: Liu
authors.forename: Han
authors.initials: H
authors.lastname: Cheng
authors.forename: Jun
authors.initials: J
authors.lastname: Feng
authors.forename: Xian-zheng
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Ren-xi
authors.initials: RX
authors.lastname: Zhuo
mesh_terms: D000327:Adsorption; D002412:Cations; D002460:Cell Line; D017077:Culture Media, Conditioned; D016895:Culture Media, Serum-Free; D004247:DNA / Q000008:administration & dosage* / Q000737:chemistry; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D002412:Cations; D017077:Culture Media, Conditioned; D016895:Culture Media, Serum-Free; D012710:Serum Albumin, Bovine; D004247:DNA