Lipid nanoparticle formulations including stereochemically defined glycomacromolecules for delivery of saRNA

Targeted and efficient delivery of nucleic acid therapeutics (NATs) is one of the major challenges in the development of next generation vaccine formulations. Glycosylated lipid nanoparticles (LNPs) utilising mannose as an active targeting ligand have the potential to improve NAT based treatments owing to their ability to bind to carbohydrate-binding protein receptors associated with immune cells. Addressing these receptors specifically results in improved cellular uptake and therefore more efficient delivery of the RNA cargo. Glycomacromolecules (GMs) with defined valency and configuration can distinguish between receptors and enhance the functionality of LNP-based formulations by pinpointing different cell types and enabling specific uptake. Therefore, in this study a library of nine discrete mannosylated GMs with a distinct stereoconfiguration were synthesised and incorporated into LNP membranes via cholesterol anchors. Established LNP formulations based on C12-200 are equipped with these GMs on their surface and evaluated for their biological performance. Surface plasmon resonance spectrometry (SPR) has been employed to investigate their binding properties with a variety of human lectins, to elucidate the avidity of both the individual GMs and the LNPs to the receptors, revealing specific lectin interactions. Additionally, the successful delivery of self-amplifying RNA (saRNA) in the glycosylated LNPs is analysed for cellular transfection efficiency in cell lines such as HEK293T/17, THP-1 and BMDC, and transfection efficiency is also evaluated in an ex vivo human skin explant model.