SUMMARY

Lipid nanoparticles (LNPs) have demonstrated safety, versatility, and clinical relevance as vehicles for RNA delivery. Currently, there are three FDA-approved LNP-RNA drugs: ONPATTRO®, the systemically administrated siRNA treatment for hereditary liver disease from Alnylam; and two intramuscular mRNA vaccines against COVID-19: SPIKEVAX® produced by Moderna and by Pfizer-BioNTech’s COMIRNATY®. However, beyond vaccination and liver targeting, LNP-RNA drugs are far from reaching their full potential. Research has shown that LNPs are capable of delivering RNA effectively to non-liver tissues, such as lung, spleen, solid tumors, and bone marrow. For the treatment and management of nervous system disorders gene therapies hold great promise but require safe and effective delivery vehicles. Therefore, a need exists to design LNPs that transfect cells in the central nervous system (CNS). Presently, LNPs with CNS tropism either i) carry ligands, ii) rely on blood-brain barrier disruption, or iii) are administrated locally. In this work, we propose the investigation of RNA delivery to the CNS upon systemic administration without the use of targeting ligands. We will first optimize the isolation of various cell types from the brain. Second, we will present mRNA delivery readouts using a liver de-targeted LNP and identify nanoparticle characteristics that will be used in subsequent high-throughput LNP screening. Finally, we will formulate and screen LNPs administrated intravenously, and characterize lead brain delivering LNPs in vivo tropism at the cellular level. Thorough this work, we will show CNS delivery for liver de-targeted LNP and demonstrate the feasibility of delivering therapeutic RNA to the brain without targeting ligands.