Abstract: The present study developed a tumor targeted gene vector by modification of PEI with G250 monoclonal antibody. G250mAb can specially combine with the G250 which is a tumor associated with antigen expressed highly in Hela cells. G250mAb was prepared from the ascites of Balb/c mice, and conjugated to PEI via disulfide bonds and generated G250mAb-PEI conjugate.G250mAb-PEI can condense plasmid DNA and form G250mAb-PEI/DNA complex, which can protect DNA from DNaseI digestion. Targeting effect and transfection efficiency of G250mAb-PEI was evaluated via co-culture technology. The results demonstrate that G250mAb-PEI can specially target the Hela cells. The transfection efficiency to Hela is two folds of HepG2 which was G250 negative. The tumor targeting effect was also demonstrated in transfection of smooth muscle cells(SMC). The transfection efficiency of SMC is almost 20 folds lower than that of Hela cells. In addition, the cytotoxicity of G250mAb-PEI which was determined by MTT assay on NIH 3T3 cells was much lower than PEI. In summary, G250mAb-PEI is a highly efficient gene vector with a low cytotoxicity and targeting effect. More work need to be done to evaluate the potential of the vector in vivo gene therapy.

Key words: Polyethyleneimine(PEI), G250mAb, Tumor targeted, Hela cell, Gene therapy