Development of Cationic Lipid-Assisted PEG-b-PLA Nanoparticle for Nucleic Acid Therapeutics

Nucleic acid-based macromolecules, including protein-expressing plasmid DNA (pDNA) and messenger RNA (mRNA), antisense oligonucleotides (ASOs), small interfering RNA (siRNA), genome editing systems, and so on, have paved new avenues for the development of therapeutic interventions against various types of diseases. Several nucleic acid-based drug have been approved for clinical application, and many more are under clinical evaluation. However, it should be noted that their clinical translation is dependent on the successful delivery to the target site and cells. Among these formulations, the clinically validated polylactide (PLA)-based nanocarriers have attracted wide attention. Unfortunately, PLA nanocarriers inefficiently encapsulated nucleic acid. In this regard, a cationic lipid-assisted PEG-b-PLA nanoparticle (CLAN) is explored to high efficiently encapsulate nucleic acid drug inside its aqueous core through double emulsion method. In this protocol, siRNA is used as a model nucleic acid drug, and the preparation and characterization of siRNA-loaded CLAN are described. And, all nucleic acid drugs could be loaded into the CLAN formulation with the same procedures. The present results demonstrate that the CLAN formulation displayed an extreme high encapsulation efficiency (>95%), an efficient cellular uptake of siRNA-loaded CLAN by tumor cells, and thereby improving the downregulation of targeted gene in vitro and in tumor models.