Plasmid DNA recovery from fermentation broths by a combined process of micro- and ultrafiltration: Modeling and application

Membrane technology for the purification of RNA and DNA therapeutics

Nucleic acid therapeutics have the potential to revolutionize the biopharmaceutical industry, providing highly effective vaccines and novel treatments for cancers and genetic disorders. The successful commercialization of these therapeutics will require development of manufacturing strategies specifically tailored to the purification of nucleic acids. Membrane technologies already play a critical role in the downstream processing of nucleic acid therapeutics, ranging from clarification to concentration to selective purification. This review provides an overview of how membrane systems are currently used for nucleic acid purification, while highlighting areas of future need and opportunity, including adoption of membranes in continuous bioprocessing.

Separation Properties of Plasmid DNA Using a Two-Stage Particle Adsorption-Microfiltration Process

Plasmid DNA is used as a vector for gene therapy and DNA vaccination; therefore, the establishment of a mass production method is required. Membrane filtration is widely employed as a separation method suitable for the mass production of plasmid DNA. Furthermore, the separation of plasmid DNA using microfiltration and ultrafiltration membranes is being investigated. Because plasmid DNA has a circular structure, it undergoes significant deformation during filtration and easily permeates the membrane, hindering the selection of separation membranes based on molecular weight. In this study, we applied affinity microfiltration to plasmid DNA purification. α-Fe₂O₃ with an isoelectric point of approximately 8 and a particle size of 0.5 μm was selected as the ligand for two-stage affinity microfiltration of plasmid DNA. In the first stage of microfiltration, the experiment was conducted at a pH of 5, and a cake of α-Fe₂O₃ with bound plasmid DNA was obtained. Next, liquid permeation (pH 9 and 10) through the cake was performed to elute the bound plasmid DNA. Plasmid DNA was eluted during the early phase of liquid permeation at pH 10. Furthermore, agarose gel analysis confirmed the usefulness of the two-stage affinity microfiltration method with adsorption and desorption for plasmid DNA purification.

Current progress on microRNAs-based therapeutics in neurodegenerative diseases

MicroRNAs (miRNAs)-based therapy has recently emerged as a promising strategy in the treatments of neurodegenerative diseases. Thus, in this review, the most recent and important challenges and advances on the development of miRNA therapeutics for brain targeting are discussed. In particular, this review highlights current knowledge and progress in the field of manufacturing, recovery, isolation, purification, and analysis of these therapeutic oligonucleotides. Finally, the available miRNA delivery systems are reviewed and an analysis is presented in what concerns to the current challenges that have to be addressed to ensure their specificity and efficacy. Overall, it is intended to provide a perspective on the future of miRNA-based therapeutics, focusing the biotechnological approach to obtain miRNAs. WIREs RNA 2017, 8:e1409. doi: 10.1002/wrna.1409 For further resources related to this article, please visit the WIREs website.