Conjugation of poly(ethylene glycol) to poly(lactide)-based polyelectrolytes: An effective method to modulate cytotoxicity in gene delivery.

Positively charged amphiphilic polymers comprising of poly(N,N-dimethylaminoethyl methacrylate) segments on both sides of a poly(l-lactic acid) segment was conjugated with poly(ethylene glycol) (DMA-PLLA-DMA@PEG). Efficient condensation of plasmid DNA by these polymers was shown. Cell toxicity studies demonstrated that the positively charged polymers with attached PEG exhibited much less cytotoxicity than polymers with no PEG in both HEK293 and Hela cell lines. PEGylation also resulted in polymers with enhanced haemo-compatibility. The positively charged polymers displayed very good DNA plasmid delivery efficiencies in both HEK293 and Hela cells.