A polylysine partially substituted with polyhydroxyalkanoyl residues and specially with gluconoyl residues was developed in order to increase the transfection efficiency by decreasing the strength of the electrostatic interaction's between the DNA and the cationic polymer. Partially gluconoylated polylysine/DNA complexes were more easily dissociated in solution and their transfection efficiency in the presence of chloroquine, evaluated with HepG2 cells, a human hepatocarcinoma line, was higher when 43 ± 4% of the ε-amino groups of polylysine were blocked with gluconoyl residues. Partially gluconoylated polylysine/plasmid complexes were efficient in transfecting different adherent as well as non-adherent cell lines. Partially gluconoylated polylysine formed highly soluble (above 100 μg/ml in DNA) complexes with DNA plasmids. In addition, partially gluconoylated polylysine bearing few lactosyl residues increased the transfection efficiency of HepG2 cells which express a galactose-specific membrane lectin.
Erbacher, P., Roche, A. C., Monsigny, M., & Midoux, P. (1997). The reduction of the positive charges of polylysine by partial gluconoylation increases the transfection efficiency of polylysine/DNA complexes. Biochimica et Biophysica Acta - Biomembranes, 1324(1), 27–36. https://doi.org/10.1016/S0005-2736(96)00204-0