Polyethylenimine-graft-poly(ethylene glycol) copolymers: influence of copolymer block structure on DNA complexation and biological activities as gene delivery system.

摘要: For two series of polyethylenimine-graft-poly(ethylene glycol) (PEI-g-PEG) block copolymers, the influence copolymer structure on DNA complexation was investigated and physicochemical properties these complexes were compared with results blood compatibility, cytotoxicity, transfection activity assays. In first series, PEI (25 kDa) grafted to different degrees substitution PEG (5 in second molecular weight (MW) varied (550 Da 20 kDa). Using atomic force microscopy, we found that strongly influenced complex size morphology:  5 kDa significantly reduced diameter spherical from 142 ± 59 61 28 nm. With increasing degree grafting, impeded lost their shape. Copolymers yielded small, compact (51 23 nm) whereas copolymers 550 resulted large diffuse structures (130 ...