RNA therapeutics are revolutionizing medicine, offering new treatment possibilities for diseases once considered undruggable. Central to the delivery of nucleic acids, especially mRNA, is the use of Lipid Nanoparticles (LNPs) – the most advanced and the only clinically approved gene delivery platform. LNPs protect mRNA from degradation, facilitate its transfer, and ensure delivery into the cell. Despite their potential, the therapeutic potency of RNA-LNPs remains limited due to suboptimal RNA delivery, with <10% of the administered RNA-LNP system reaching the cytoplasm. To this end, crucial gaps persist in our understanding of LNP structure, integrity and their impact on trafficking and RNA delivery. CryoLipNano aims to advance our knowledge on LNP ultrastructure and intracellular dynamics, by linking – for the first time – lipid composition, morphology, LNP integrity, mRNA localization and trafficking after endocytosis. By integrating physical chemistry with cutting-edge cryo-electron microscopy (cryoEM), advanced imaging techniques, and proteomic analysis, this study will address critical knowledge gaps, ultimately leading to the rational design of second-generation LNP platforms with enhanced efficiency and potency. Moreover, CryoLipNano will establish the first RNA-LNP research hub at the host institute and, alongside with the ERA Chair's launch of the country's first cryoEM facility, will create a new line of expertise in RNA-LNP characterization by cryoEM. This expertise will be valuable not only in Greece, but also for entities across Europe and globally. CryoLipNano will also focus on disseminating the lab’s presence, educating the scientific community and the public about RNA therapeutics and their structural analysis, and inspiring young scientists. Finally, the high-level science and training the fellow will receive, will significantly advance her expertise and enhance her future employability in the field of nanomedicine and RNA therapeutics.