title: Linear poly(amido amine)s with secondary and tertiary amino groups and variable amounts of disulfide linkages: synthesis and in vitro gene transfer properties.
abstract: A group of novel poly(amido amine) homo- and copolymers (PAAs) containing secondary and tertiary amine groups in their main chain and different structures in the bisacrylamide segments were synthesized and evaluated as non-viral gene delivery vectors. Among these, also the disulfide-containing cystaminebisacrylamide was employed as a (co)monomer, yielding PAAs with variable amounts of bioreducible disulfide linkages in the main chain. Michael addition the trifunctional 1-(2-aminoethyl) piperazine to equimolar amounts of the appropriate bis(acrylamide) yielded linear polymers as was elucidated by their (13)C NMR spectra. The polymers possess buffering capacities between pH 5.1 and pH 7.4 higher than branched polyethylenimine (pEI) and are able to efficiently condense DNA into nanosized (<150 nm) and positively charged complexes. Transfection experiments with COS-7 cells showed that polyplexes from PAAs with disulfide linkages give significant higher transfections than those from PAAs lacking the disulfide linkage, and XTT assays showed that these polymers are essentially non-toxic. Variation of the disulfide content revealed that polyplexes of PAA copolymers with appropriate disulfide content have largely improved biophysical properties, yielding enhanced levels of gene expression along with low toxicity. The results demonstrate that bioreducible poly(amido amine)s are a very promising class of polymers for safe and efficient gene delivery.
authors.affiliation: Department of Biomedical Chemistry, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Chao
authors.initials: C
authors.lastname: Lin
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Zhong
authors.forename: Martin C
authors.initials: MC
authors.lastname: Lok
authors.forename: Xulin
authors.initials: X
authors.lastname: Jiang
authors.forename: Wim E
authors.initials: WE
authors.lastname: Hennink
authors.forename: Jan
authors.initials: J
authors.lastname: Feijen
authors.forename: Johan F J
authors.initials: JF
authors.lastname: Engbersen
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000818:Animals; D019556:COS Cells; D002470:Cell Survival / Q000187:drug effects; D002522:Chlorocebus aethiops; D004247:DNA / Q000378:metabolism; D004220:Disulfides / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D017930:Genes, Reporter; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007763:Lac Operon; D009682:Magnetic Resonance Spectroscopy; D008689:Methacrylates / Q000378:metabolism / Q000633:toxicity; D015394:Molecular Structure; D009757:Nylons / Q000378:metabolism / Q000633:toxicity; D010316:Particle Size; D010879:Piperazines / Q000737:chemistry; D011073:Polyamines / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D011094:Polyethyleneimine / Q000378:metabolism / Q000633:toxicity; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D014162:Transfection / Q000379:methods*
chemical_list: D000178:Acrylamides; D004220:Disulfides; D008689:Methacrylates; D009757:Nylons; D010879:Piperazines; D011073:Polyamines; D011108:Polymers; C407037:poly(2-(dimethylamino)ethyl methacrylate); C033005:aminoethylpiperazine; D011094:Polyethyleneimine; D004247:DNA