Dextran–glycidyltrimethylammonium chloride conjugate/DNA nanoplex: A potential non-viral and haemocompatible gene delivery system

Non-viral gene carriers have attracted great interests for their unique properties. Cationic polymers have been in focus nowadays. Dextran is one of the most widely studied polymer in terms of gene therapy and in vivo disposition. But its applications are limited by its own drawbacks. To overcome the drawback, we have modified dextran using glycidyltrimethylammonium chloride (GTAC) bearing cationic groups. Nanoplexes were prepared using the derivative and calf thymus DNA (ctDNA) by reducing the surface charge and size of ctDNA. Complexation and stability of the nanoplex was proved using agarose gel electrophoresis and by Ethidium bromide (EtBr) displacement assay. Acid base titration studies were done to determine its buffering capacity. Derivatization was confirmed using NMR. Protection of ctDNA from nuclease digestion was evaluated. Stability of the nanoplex towards plasma components was analyzed. Its interactions with blood components were tested by haemolysis and aggregation studies. In vitro cytotoxicity studies have been done to investigate the effect of nanoplex on HepG2 cells by MTT assay. This derivative has been proved to be feasible in transfection. The above investigations prove the capability of dextran modified with GTAC as a promising non-viral and haemocompatible gene delivery agent.