Pristine Multi-walled carbon nanotubes for a rapid and efficient plasmid DNA clarification

Abstract

Therapeutic approaches based on nucleic acids to modulate cell activity have recently gained attention. These molecules arise from complex biotechnological processes, requiring effective manufacturing strategies, high purity, and precise quality control to be used as biopharmaceuticals. One of the most critical and time-consuming steps for nucleic acids-based biotherapeutics manufacturing is their purification, mainly due to the complexity of the extracts. In this study, a simple, efficient, and reliable method to isolate and clarify plasmid DNA (pDNA) from complex samples is described. The method is based on the selective capture of RNA and other impurities, using pristine carbon nanotubes (CNTs). Multi-walled CNTs (MWCNTs) with different diameters were studied to determine their adsorption capacity and to address their ability to interact and distinguish between nucleic acids. The results revealed that MWCNTs preferentially interact with RNA and that smaller MWCNTs present a higher adsorption capacity, as expected by the higher specific surface area. Overall, this study showed that MWCNTs significantly reduce the levels of impurities, namely RNA, gDNA, and proteins, by approximately 83.6 % compared to their initial level, enabling the recovery of clarified pDNA in solution while maintaining its stability throughout the recovery process. This method facilitates the pre-purification of pDNA for therapeutic applications.