A multidisciplinary team delineated the detailed shapes and structural heterogeneity of lipid nanoparticles (LNPs) used for RNA delivery, linking particle architecture to delivery performance. Using orthogonal biophysical techniques, researchers visualized distinct LNP morphologies and correlated those forms with cellular delivery efficiency and inflammatory profiles. The work, published in Nature Biotechnology, provides a framework for rational LNP design to match formulations to tissues or indications rather than treating LNPs as a single class. LNP shape and composition tuning may accelerate translation of RNA therapies by improving potency and safety profiles.