Abstract: This disclosure relates to ionizable lipid-based lipid nanoparticles for delivery of mRNA encoding glucose-6-phosphatase. Lipid nanoparticle/mRNA therapies of the invention increase and/or restore deficient levels of glucose-6-phosphatase expression and activity in subjects and are useful for the treatment of glycogen storage disease type 1a (GSD-Ia). Lipid nanoparticle/mRNA therapies of the invention increase glucose production and reduce the abnormal accumulation of glycogen and glucose-6-phosphate associated with GSD-Ia.

Abstract: The disclosure features target cell delivery lipid nanoparticle (LNP) compositions that allow for enhanced delivery of agents, e.g., nucleic acids, such as therapeutic and/or prophylactic RNAs, to target cells, in particular liver cells and/or splenic cells. The LNPs comprise an effective amount of a target cell delivery potentiating lipid such that delivery of an agent by a target cell target cell delivery LNP is enhanced as compared to an LNP lacking the target cell delivery potentiating agent. Methods of using the target cell target cell delivery LNPs for delivery of agents, e.g., nucleic acid delivery, for protein expression, and for modulating target cell activity are also disclosed.

Abstract: The present disclosure is based, at least in part, on the discovery that high-purity PEG lipids exhibit superior physical and biological properties, particularly when used in lipid nanoparticle (LNP) formulations. Therefore, the present disclosure provides PEG lipids at a recommended purity, e.g., for use in formulations, such as LNP formulations. The present disclosure also provides LNPs comprising the high-purity PEG lipids, and methods for delivering therapeutic agents to a subject using the same.