Interaction of non-lamellar lipid vectors for RNA delivery with bio-relevant interfaces: A Neutron Reflectometry study

RNA technologies are expected to revolutionize the treatment and/or prevention of a host of diseases. The design of appropriate vectors, able to efficiently complex RNA, deliver it to cells and release it inside cytoplasm, is key to boost the translation of RNA systems into the clinic. We have recently designed of non-lamellar lipid particles for RNA delivery, where glyceryl-monooleate is mixed with (i) a biocompatible cationic lipid, (ii) a pH-sensitive ionizable lipid or (iii) a mixture of (i) and (ii). The peculiar topology of these systems, alongside their cationic nature or pH sensitivity, is expected to boost endosomal membrane destabilization, to enhance endosomal escape. Preliminary light and X-ray scattering experiments confirmed successful encapsulation of model RNA (polyadenylic acid (polyA)) within such systems, while in vitro tests highlighted high RNA-delivery ability, especially for particles formulated with both cationic and ionizable lipids. Through Synchrotron SAXS experiments (ID02, ESRF (March 2024)), we further explored the interactions of polyA-loaded particles with model vesicles for early and late endosomal membranes. Here we aim to extend this investigation, employinf neutron reflectometry to study the interaction of RNA-loaded non-lamellar particles with supported lipid bilayers, mimicking endosomal or plasma membranes. Results will contribute establishing a relationship between the topology of the vector and its RNA delivery efficiency.