# Optimizing C14120-based LNPs for in vitro and in vivo mRNA delivery

## TL;DR

This study identifies lipid nanoparticle formulations that efficiently deliver mRNA in cells and target specific organs in living organisms.

## Contribution

The study introduces a high-throughput screening method to optimize lipid nanoparticles for tissue-specific mRNA delivery.

## Key findings

- Lipid composition correlates with particle size and transfection efficiency in four cell lines.
- Certain LNP formulations show organ-specific targeting in vivo, such as lung, liver, and spleen.
- A lung-targeting LNP candidate demonstrated high specificity, while a liver-targeting one showed lower specificity.

## Abstract

Lipid nanoparticles (LNPs) have proven to be an effective delivery system for RNA therapeutics. The chemical composition of LNPs determines their functional delivery efficiency and targeting properties, which vary between in vitro and in vivo contexts. Here, we have systematically characterized and compared 25 novel C14120-based LNP formulations for mRNA delivery in vitro and assessed in vivo mRNA expression and biodistribution using deep sequencing of DNA barcodes in a pooled LNP-mRNA library. In vitro experiments showed correlations of lipid composition with particle size and mRNA transfection efficiency in 4 different cell lines of distinct tissue and species origin. In vivo experiments employed a pooled LNP delivery of luciferase mRNA in combination with a multiplexed barcode system and identified LNP compositions with organ-specific targeting properties. Individual validation of three selected LNP candidates based on mRNA expression analysis confirmed high specificity for the lung-targeting candidate, lower specificity for the liver-targeting candidate, and inconclusive results for the spleen-targeting candidate. These findings identify LNP formulations with promising potential for in vitro and in vivo organ-targeted delivery.

This study uses high-throughput screening to optimize lipid nanoparticles (LNPs) for tissue targeting. It reveals key parameters influencing LNP performance in characterization, mRNA transfection efficiency, and cell origin specificity, both in vitro and in vivo. Our findings provide insights for designing next-generation LNP candidates with enhanced delivery efficiency.