September
22,
2023
(Drug DELIVERY Specific Seminar)
Lipid nanoparticles (LNPs) are gaining traction in nucleic acid delivery following the success of two mRNA vaccines against COVID-19. As one of the constituent lipids on LNP surfaces, PEGylated lipids (PEG-lipids) play an important role in defining LNP physicochemical properties and biological interactions. Previous studies indicate that LNP performance is modulated by tuning PEG-lipid parameters, including PEG size and architecture, carbon tail type and length, and PEG-lipid concentration. Owing to these numerous degrees of freedom, a high-throughput approach is necessary to fully understand LNP behavioral trends over a broad range of PEG-lipid variables. We report a low-volume, high-throughput screening (HTS) workflow for the preparation, characterization, and in vitro assessment of LNPs loaded with a therapeutic antisense oligonucleotide (ASO). A library of 54 ASO-LNP formulations with distinct PEG-lipid compositions was prepared using a liquid handling robot and assessed for their gene silencing efficacy in murine neurons. Our results show anionic PEG-lipid concentration regulates LNP particle size. In contrast, PEG-lipid carbon tail length controls ASO-LNP gene silencing activity, with up to 5-fold lower mRNA expression achieved in neurons treated with ASO-LNPs as compared to naked ASO. We then scaled up the HTS hits using a well-established microfluidic formulation technique, demonstrating a smooth translation of ASO-LNP properties and in vitro efficacy across different formulation scales. Our HTS workflow can screen additional LNP multivariate parameters with significant time and material savings, guiding the selection and scale-up of optimal formulations for nucleic acid delivery to various cellular targets.
Hosted by Glen Kwon
