8Chen QR,Zhang L,Stass SA,et al.Branched co-polymers of histidine and lysine are efficient carriers of plasmids.Nucleic Acids Res,2001;29(6)∶1334
9Boussif O,Lezoualc'h F,Zanta MA,et al.A versatile vector for gene and oligonucleotide transfer into cells in culture and in vivo:polyethylenimine.Proc Natl Acad Sci U S A,1995; 92(16)∶7297
10Benns JM,Mahato RI,Kim SW.Optimization of factors influencing the transfection efficiency of folate-PEG-folate-graft-polyethylenimine.J Control Release,2002;79(1-3)∶255
