title: Reducible poly(amido ethylenimine) directed to enhance RNA interference.
abstract: Designing synthetic macromolecular vehicles with high transfection efficiency and low cytotoxicity has been a major interest in the development of non-viral gene carriers. A reducible poly(amido ethylenimine) (SS-PAEI) synthesized by addition copolymerization of triethylenetetramine and cystamine bis-acrylamide (poly(TETA/CBA)) was used as a carrier for small interference RNA (siRNA). Poly(TETA/CBA) could efficiently condense siRNA to form stable complexes under physiological conditions and perform complete release of siRNA in a reductive environment. When formulated with VEGF-directed siRNA, poly(TETA/CBA) demonstrated significantly higher suppression of VEGF than linear-polyethylenimine (PEI) (L-PEI, 25kDa) in human prostate cancer cells (PC-3). After 5h of transfection, substantial dissociation and intracellular distribution of siRNA was observed in the poly(TETA/CBA) formulation, but not in the L-PEI formulation. The triggered release of siRNA by reductive degradation of poly(TETA/CBA) in the cytoplasm may affect the RNAi activity by increasing cytoplasmic availability of siRNA. These results suggest that the rational design of non-viral carriers should involve considerations for intracellular dissociation and trafficking of a nucleic acid drug to maximize its effect, in conjunction with formation of stable complexes under physiological conditions.
authors.affiliation: CCCD/Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Ji
authors.initials: J
authors.lastname: Hoon Jeong
authors.forename: Lane V
authors.initials: LV
authors.lastname: Christensen
authors.forename: James W
authors.initials: JW
authors.lastname: Yockman
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Zhong
authors.forename: Johan F J
authors.initials: JF
authors.lastname: Engbersen
authors.forename: Won
authors.initials: W
authors.lastname: Jong Kim
authors.forename: Jan
authors.initials: J
authors.lastname: Feijen
authors.forename: Sung
authors.initials: S
authors.lastname: Wan Kim
mesh_terms: D001388:Aziridines / Q000737:chemistry*; D045744:Cell Line, Tumor; D004337:Drug Carriers / Q000737:chemistry; D006801:Humans; D008297:Male; D008422:Materials Testing; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics* / Q000493:pharmacokinetics*; D014162:Transfection / Q000379:methods*
chemical_list: D001388:Aziridines; D004337:Drug Carriers; D034741:RNA, Small Interfering; C033132:aziridine