title: New cationic biodegradable poly(urethane-co-ester): synthesis, structural characterization, modification and gene delivery.
abstract: To improve the transfection efficiency of poly(urethane-co-ester) and the cytotoxicity of PEI25k with DNA, we synthesized a new poly(urethane-co-ester), PUE, bearing ester linkages and amino groups in the backbone and urethane linkages in the side-chain, and then prepared a binary mixture,  PUE-PEI25k, using a physical blending method. The structure of PUE was confirmed by FT-IR and NMR spectra. Both poly(urethane-co-ester), PUE, and binary mixture PUE-PEI25k, readily self-assembled with plasmid DNA (pCMV-βgal) in a HEPES buffer, were characterized by dynamic light  scattering. The results revealed that PUE and PUE-PEI25k were able to self-assemble plasmid DNA into PUE/DNA and PUE-PEI25k/DNA nano-complexes small enough to enter a cell through endocytosis. Titration studies were performed to determine the buffering capacities of PUE and PUE-PEI25k. The  COS-7 cell viability in the presence of PEI25k, PUE and PUE-PEI25k was studied. At low mass ratio of PUE/PEI25k (150:1), it was found that the PUE-PEI25k/DNA complexes were able to transfect COS-7 cells in vitro with a high efficiency comparable to a well-known gene carrier, PEI25k/DNA.  The results indicate that the binary mixture PUE-PEI25k is an attractive cationic carrier for gene delivery and an interesting candidate for further study.
authors.affiliation: Department of Biotechnology, Chia-Nan University of Pharmacy and Science, 60 Erh-Jen Road, Sec 1, Jen-Te, Taiwan, ROC.
authors.forename: Wei-Yang
authors.initials: WY
authors.lastname: Chang
authors.forename: Yu-Che
authors.initials: YC
authors.lastname: Hsiao
authors.forename: Min-Da
authors.initials: MD
authors.lastname: Shau
mesh_terms: D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000737:chemistry* / Q000633:toxicity; D006868:Hydrolysis; D010316:Particle Size; D010957:Plasmids / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011091:Polyesters / Q000138:chemical synthesis* / Q000737:chemistry* / Q000633:toxicity; D011140:Polyurethanes / Q000138:chemical synthesis* / Q000737:chemistry* / Q000633:toxicity; D014162:Transfection / Q000379:methods*
chemical_list: D004337:Drug Carriers; D011091:Polyesters; D011140:Polyurethanes; C081821:microthane foam; D004247:DNA