A Peptide Barcode Based Approach for Efficient in vivo Screening of RNA Delivery Systems

Abstract The clinical advancement of mRNA therapeutics for diverse applications, facilitated by lipid nanoparticles (LNPs), has demonstrated the promise of LNPs as a delivery vector. Continued exploration of LNPs for application in new disease areas requires identification and optimisation of leads in a high throughput way. Currently available high throughput in vivo delivery system screening platforms are better suited to screen for cellular uptake but less so for functional cargo delivery. We have therefore developed a Proteomics Associated LNP Screening (PALS) platform which measures functional delivery of LNPs using unique peptide ‘barcodes’. We report on the design and selection of the peptide barcodes and the evaluation of these barcodes for the screening of LNPs. We show that proteomic analysis of peptide barcodes correlates with quantification and efficacy of barcoded reporter proteins both in vitro and in vivo and, that the ranking of selected LNPs using peptide barcodes in a pool correlates with ranking using alternative methods in groups of animals treated with individual LNPs. We show that this system is sensitive, selective, and capable of reducing the size of an in vivo study by at least 10-fold, thus accelerating the discovery of new technologies for mRNA delivery.