Modified Pectin-Based Carrier for Gene Therapy: The Effect of Ultrasound on Plasmid DNA Delivery into the Nucleus of Glioma Cells In Vitro

We explored a novel gene therapy approach based on natural polysaccharides as carriers for targeted delivery of pDNA to cancerous cells. Our hypothesis is based on highly specific carbohydrate interaction between the natural polysaccharide pectic galactan and the galectin-3 cell protein that is highly expressed in a variety of cancer cells, such as glioma. This interaction will result in higher concentrations of pectic galactan/pDNA complexes at given cell surface, and therefore, increase their chances for internalization. Ultrasound (US) was utilized as a mean for overcoming intracellular barriers. Q-galactan was prepared by modifying quaternary ammonium groups on pectic galactan. Q-galactan was found to form globular condensed complexes with pDNA with size suitable for internalization to the cell through endocytosis. The complexes were proven to be non-toxic to C6 rat glioma cells line, and were able to penetrate the cell membrane and approach the nucleus within 24 hours. US irradiation was found to enhance pDNA nuclear delivery. This study demonstrates that Q-galactan is a potential carrier for gene therapy and that US can be used in order to overcome intracellular berries and improve transfection.