Construction of in vivo mRNA delivery systems

Project Summary Cell-specific drug delivery represents one of the most important research areas in the field of drug delivery. Particularly, there are formidable challenges for in vivo mRNA delivery. For example, therapeutic window for current delivery systems is relatively narrow. A large number of cell types cannot be efficiently delivered in vivo. Biodegradability of the delivery materials remains a concern. In order to address the challenges, the goals of our research program are: 1) to develop diverse lipid derivatives; 2) to construct mRNA delivery systems; 3) to examine the delivery efficiency, pharmacokinetics, and safety profile of these systems in animal models. In our preliminary studies, we developed functionalized lipid-like nanoparticles for in vivo mRNA delivery and base editing. The lead material was able to produce human factor VIII at a normal physiological level in hemophilia A mice. The effective base editing was also achieved at low doses in mice. Meanwhile, we constructed vitamin derived lipid nanoparticles, which enabled adoptive macrophage transfer for eliminating multidrug resistant (MDR) bacteria in mouse models. Moreover, we showed promising mRNA delivery in other cell types, such as stem cells and reproductive cells. Additionally, we systematically investigated the untranslated regions (UTRs) of mRNAs in order to enhance protein production. Through a comprehensive analysis of endogenous gene expression and de novo design of UTRs, we identified an optimal combination of 5’ and 3’ UTR, termed as NASAR, which was significantly more efficient than the tested endogenous UTRs. These preliminary data provide the scientific foundation to address the delivery challenges of mRNA-based therapeutics. In this proposal, we propose four directions for mRNA delivery in vivo: (1) to optimize N1,N3,N5-tris(2-aminoethyl)benzene-1,3,5- tricarboxamide (TT) lipid derivatives for hepatocytes delivery; (2) to investigate vitamin lipid derivatives for macrophages delivery; (3) to develop glycolipid derivatives for stem cells delivery; (4) to conceive novel lipid derivatives for reproductive cells delivery. We will prove the concept of cell-specific delivery systems in animal models. Our research goal is to translate the innovations of this research strategy to develop better mRNA delivery tools to treat diverse diseases.