Researchers have designed a non-toxic modified polymer 'pullulan' from fungus that can deliver genes to targeted liver cells1 .

To replace polymer-based gene delivery vectors which have drawbacks such as toxicity and non-compatibility with blood, the researchers focused on pullulan, a type of polysaccharide. They modified it using glycidyl trimethyl ammonium chloride and attached the modified polymer with calf thymus DNA forming three nanoplexes (CP1, CP2 and CP3).

The nanoplexes were found to be compatible with red blood cells (RBC). CP3 didn't cause any aggregation of RBC even at 1mg/ml concentration. In toxicity studies with human liver cancer cells, more than 90 per cent cells were found to be viable in the case of CP3.

The study also showed strong uptake of nanoplexes by liver cells. It was observed that the modified polymer was not accumulating but getting removed from the body of mice. CP3 seems to be a promising blood compatible candidate as an efficient gene carrier for liver targeting, the researchers say.