Blood compatibility and in vitro transfection studies on cationically modified pullulan for liver cell targeted gene delivery

One of the major drawbacks of non-viral vector based gene delivery is the toxicity effects related to their positive charge. The aim of this work is to develop a cationic pullulan that can be used for gene delivery applications targeted to liver cells. Cationic groups were introduced by reacting varying amounts of glycidyl trimethyl ammonium chloride with pullulan. The cationic derivatives readily formed polyionic complexes with DNA and the size and zeta potential of these complexes were evaluated. The cytotoxicity and blood compatibility of cationic pullulan (CP) derivatives were assessed and compared to polyethyleneimine. Based on the cytotoxicity and blood compatibility test results CP3 was taken for further studies. Liver binding affinity of the modified pullulan CP3 was tested in vitro on hepatocytes and in vivo on mice. The complex was found to be stable in the presence of plasma as observed from gel retardation assay. This study focuses on the blood compatibility of the cationic pullulan, physico-chemical characterization and uptake of the nanocomplex by hepatocytes and in vitro transfection.