Synthesis, characterization, and gene transfer application of poly(ethylene glycol-b-ethylenimine) with high molar mass polyamine block

Biomacromolecules. 2006 Oct;7(10):2863-70. doi: 10.1021/bm060499a.


The study of ethyloxazoline/methyloxazoline (EtOXZ/MeOXZ) copolymerization, initiated by methyl tosylate (MeOTs), showed that (i) incorporation of MeOXZ units into random copolymer becomes effective over DP = 100 and (ii) propagation process proceeds with negligible transfer to monomer up to a DP of 400 despite the presence of MeOXZ in the polymerization medium. These results produced random poly(EtOXZ-co-MeOXZ) copolymers with various molar composition ratios in alkyloxazoline units. The close values found for the comonomer reactivity ratios in acetonitrile (r(1MeOXZ) = 1.18; r(2EtOXZ) = 0.34) implied a random chain organization in short sequences of each repeating unit, which was an important parameter in view of the optimization of their subsequent modification: the alkaline hydrolysis was successfully achieved when the MeOXZ unit content of the polyoxazoline chains reached 75%. Using these results, the diblock copolymer poly(ethylene glycol-b-(ethyloxazoline-co-methyloxazoline)) (poly(EG-b-(EtOXZ-co-MeOXZ))) with high DP was synthesized by cationic copolymerization of EtOXZ/MeOXZ comonomers using CH(3)-PEG(2kDa)-Ts as macroinitiator. The comonomer composition of this new compound was adjusted in order to optimize the hydrolysis step and obtain finally the diblock copolymer poly(ethylene glycol-b-ethylenimine) (poly(EG-b-EI)). The high molar mass of this copolymer was confirmed both by (1)H NMR and SANS measurements. Gene delivery experiments showed that the copolymer has significant DNA transfection capacities.

MeSH terms

  • Biocompatible Materials / chemistry*
  • Cations
  • Cell Culture Techniques / instrumentation*
  • Cell Culture Techniques / methods
  • Cell Line
  • Cell Line, Tumor
  • Cell Survival
  • DNA / chemistry
  • Gene Transfer Techniques*
  • Humans
  • Hydrolysis
  • Polyamines / chemistry*
  • Polyethylene Glycols / chemistry*
  • Polyethyleneimine / chemistry*
  • Polymers / chemistry
  • Transfection


  • Biocompatible Materials
  • Cations
  • Polyamines
  • Polymers
  • Polyethylene Glycols
  • Polyethyleneimine
  • DNA