Separation and Purification of Nanoparticle bioproduct: Ion-exchange chromatography of plasmid DNA nanoparticle

There has been much interest generated in the recovery of nanoparticulate (nanoparticle) bioproducts(second generation of biotechnological products) such as plasmid DNA as putative gene therapy vectors[1].this nanoparticulates are characterized by a critical size range(10-300nm diameter),wich distinguish them from protein macromolecules[2]. Plasmid purification by anion-exchange chromatography takes advantage of the interaction between the negatively charged phosphate groups in the DNA back bone and the positively charged ligands on the matrix. The shape and size of the molecules also may play an important role, particularly in the separation of plasmid variants. In fact in some anion exchangers, the more compact supercoiled form, which have a higher charge density, elute later than the open circular forms which have a lower, overall, charge density. Anion-exchange chromatography is the most popular chromatography technique in plasmid DNA nanoparticle purification as it offers the advantages of rapid separation, no solvent requirement and a wide selection of industrial media [3].