AbstractHerein, we developed a novel biodegradable gene carrier for rapid endothelialization of endothelial cells (ECs) in vitro. Three triblock amphiphilic copolymers, methoxy-poly(ethylene glycol)-block-poly(3(S)-methyl-2,5-morpholinedione-co-glycolide)-graft-polyethyleneimine (mPEG-b-P(MMD-co-GA)-g-PEI) with different 3(S)-methyl-2,5-morpholinedione and glycolide contents were synthesized. Microparticles (MPs) were obtained via self-assembly of these copolymers. The hydrophobic core composed of P(MMD-co-GA) segments provide crosslinking points for numbers of PEG and short PEI chains to form a highly hydrophilic and positively charged corona/shell of MPs. Using these MPs, potential genes (ZNF580) for rapid endothelialization were efficiently transported into EA.hy926 cells. Because of the hydrophilic PEG chains and low molecular weight PEI in the triblock copolymers, the cytotoxicity of these MPs and their complexes with pEGFP–ZNF580 was decreased significantly. The transfection efficacy of MPs/pEGFP–ZNF580 complexes was as high as Lipofectamine™ 2000 reagent to EA.hy926 cells in vitro. The proliferation and migration of EA.hy926 cells were improved greatly by the expression of pEGFP–ZNF580 after 60 hours. Our results indicated that the mPEG-b-P(MMD-co-GA)-g-PEI based MPs could be a suitable non-viral gene carrier for ZNF580 gene to enhance rapid endothelialization.