A new insight in gellan microspheres application to capture a plasmid DNA vaccine from an Escherichia coli lysate

This work explores the application of divalent cations-crosslinked gellan microspheres to capture pDNA from a complex Escherichia coli lysate through the batch method. Copper-crosslinked gellan microspheres allowed 15.61% of pDNA recovery with 2.42% of purity, through a strategy based on immobilized metal affinity chromatography, by manipulating the pH and ionic strength. Another strategy was developed, including a previous clarification step with ammonium sulfate, which improved the recovery percentage to 32.41%, and the purity degree to 12.43%. Moreover, copper-crosslinked gellan microspheres were functionalized with polyethylenimine ligands, which resulted into a significant improvement of pDNA capture (88.09% of recovery yield), although the purity has been 3.18%. Considering that E. coli lysate initially has 1.07% pDNA, these simple strategies allow the pDNA capture and lysate clarification to be directly applied in a purification process without the need of organic solvents, reducing the environmental impact for pharmaceutical industry.