Researchers at the University of Pennsylvania reported a redesigned class of lipid nanoparticles (aroLNPs) that markedly reduce liver delivery and instead concentrate mRNA in lymph nodes, boosting antigen‑specific immune responses in mice. Published in JACS, the work describes aromatic ionizable lipids with biodegradable disulfide bonds and tunable tail lengths; the best constructs showed roughly tenfold lower liver mRNA delivery than LNPs built with Moderna’s ionizable lipid while preserving lymph node tropism. The authors presented mechanistic data on regiochemistry and hydrophobicity effects; the result offers a delivery strategy to focus vaccines and immunotherapies on immune tissues and potentially reduce off‑target exposure.