Microfluidic assembly of lipid nanoparticles for delivery of antisense oligonucleotides.

Microfluidically (MF) synthesized lipid nanoparticles (LNPs) for antisense oligonucleotides (ODN) delivery have been shown to be superior to those prepared by bulk mixing (BM). In this study, a 5-inlet MF chip was used to synthesize LNPs loaded with LOR-2501, an antisense ODN targeting the ribonucleotide reductase R1 subunit. The size distribution of ODN- LNPs was measured by dynamic light scattering. The cytotoxicity of ODN- LNPs was determined by MTS assay. Gene silencing activity of ODN- LNPs was investigated by qRT-PCR and by Western blot. Results showed that MF synthesis produced ODN-LNPs that have lower average size and polydispersity values. The highest antisense activity was shown by LNs synthesized by the MF T2 chip, with downregulation of R1 mRNA by 32.5%. In conclusion, given their simplicity, affordability and reproducibility, MF is an attractive method for synthesis of LNs for ODN delivery.