Development of peptoid-based barcodes for in vivo high-throughput screening of targeted nucleic acid delivery

PROJECT SUMMARY / ABSTRACT The proposed project aims to deliver a research tool that supports accurate and resource- efficient biodistribution studies involving a library of gene-encapsulated nanoparticles. The state-of-the-art technology to perform in vivo high-throughput screening of non-viral gene

delivery vectors is DNA/RNA barcoding, where oligonucleotides of unique sequence are used as identifiable and quantifiable label for individual nanoparticles in a pooled mixture. However, notwithstanding the exponentially growing number of novel gene-carrying nanoparticles, researchers have not been equally attracted to in vivo high-throughput screening via this

barcoding technology. The long-term objective of our proposed study is to offer a broadly accessible and therefore accepted tool for non-viral gene delivery research, by offering several key innovative elements that address the shortcomings of the current method. Specifically, our novel barcodes composed of deuterated peptoid, labelled Deuterated Oligo-

Peptoid Add-on as Nanoparticle Tracer (DOPANT), will demonstrate inert nanoparticle loading process, biological stability, simplified extraction and purification protocols, as well as affordable and sensitive detection method. To that end, the Emmitte group will synthesize DOPANT barcodes, a library of 3-mer peptoids with varying molecular weights based on the

degree of deuteration and the choice of monomer, to be co-loaded with the genetic cargo into nanoparticle formulations (Aim 1). The Kim group will then validate the DOPANT barcode- labeled nanoparticles and their applications in a high-throughput biodistribution study. The parameters in formulating a cocktail solution of multiple DOPANT-loaded nanoparticles will be

fine-tuned for optimal performance in biodistribution screening (Aim 2). Finally, DOPANT barcode technology will be validated through a proof-of-principle, biodistribution study of 10 different mRNA-loaded lipid nanoparticles in healthy mice of two strains and both sexes (Aim 3). This collaborative project brings in the complementary expertise of two research groups to

develop a novel enabling tool that can advance and accelerate the path to clinical translation for many existing and forthcoming nanoparticle designs.