Surface charge of LNP and V-ATPase activity of target cell synergize in functional delivery of nucleic acid in vitro and in vivo.

Efficient delivery of nucleic acid therapeutics by lipid nanoparticles (LNPs) depends on complex interaction between vectors and targets. Here, we propose a model wherein LNP tropism is orchestrated synergistically by the particle's surface charge and the target cell's endo/lysosomal vacuolar H+-ATPase (V-ATPase) activity. In vitro, neutral LNPs transfected Fed cells (cells in +FBS medium) with optimal V-ATPase activity more efficiently than -FBS cells, while positively-charged LNPs transfected -FBS cells (cells in -FBS medium) with reduced V-ATPase activity more efficiently than Fed cells. In vivo, this synergy was applicable to liver, versus lung tropism of neutral versus positively-charged LNPs respectively. In addition, pre-condition of the reticuloendothelial system (RES) with empty LNPs enhanced functional delivery to lung but not liver mediated by positively-charged LNPs. Pharmacological inhibition of V-ATPase activity reduced in vitro and in vivo delivery mediated by neutral LNPs. On the other hand, elevating V-ATPase activity via genetic knockdown of ATP6-V1H enhanced in vitro delivery mediated by negatively-charged LNPs. Moreover, we found that the major components of protein corona adsorbed to in vivo neutral LNPs and positively-charged LNPs were shared by each other, except that the latter contained higher levels of coagulation factors and hemoglobins. In summary, our findings uncover a synergistic interaction between LNPs and targets in vitro and in vivo orchestrated by surface charge of LNP and V-ATPase activity of target.