CORE: Cholesterol Altered Lipid Nanoparticles for Splenic Expression of mRNA Payloads.

A central challenge within the field of nanomedicine is synthesizing and formulating vectors capable of extrahepatic delivery. mRNA lipid nanoparticles (LNPs) are no exception as most lipid-based formulations, when administered systemically, facilitate delivery and expression of mRNA to the liver. To address this delivery challenge, we developed a new class of LNPs-termed ChOlesterol alteREd lipid nanoparticles (CORE LNPs)-designed to shift mRNA expression away from the liver and toward the spleen, a central organ for systemic immune activation. To do so, we interfaced material synthesis with computational characterization to develop a series of novel cholesterol analogs which were incorporated alongside formulation components used for mRNA delivery. These were then optimized through design of experiment to generate 78 discrete formulations and were assessed for their physical properties, cellular uptake, and endosomal escape capabilities in vitro. Importantly, in vivo studies demonstrated that CORE LNPs were well-tolerated and achieved highly selective mRNA expression in the spleen following intravenous administration. These results suggest that interfacing synthesis with computational characterization of novel cholesterol derivatives may modulate both nanoparticle behavior and organ-level targeting, offering a promising strategy for developing spleen-specific mRNA therapies for vaccination and immune modulation.