Amino acid supplementation enhances in vivo efficacy of lipid nanoparticle-mediated mRNA delivery in preclinical models.

Simulated physiologic metabolic conditions down-regulated certain amino acid metabolic programs in vitro, indicating that the physiologic metabolome imposes constraints on mRNA expression from LNPs.

• An in vitro system was used to model physiologic metabolic conditions.
• Under these conditions, specific amino acid metabolic programs were found to be down-regulated.
• This finding established that cellular metabolism influences LNP delivery efficacy.

Supplementation with an optimized formulation of methionine, arginine, and serine (AAS) enhanced LNP uptake and mRNA cargo expression in epithelial cells in vitro.

• The amino acid supplement (AAS) consisted of methionine, arginine, and serine.
• Enhancement was observed specifically in epithelial cells in vitro.
• Both LNP uptake and downstream mRNA expression were improved by AAS supplementation.

Coadministration of AAS with LNPs led to a 5- to 20-fold improvement in mRNA expression across various cell types and lipid formulations in vitro.

• The improvement ranged from 5- to 20-fold depending on cell type and lipid formulation.
• The effect was observed across multiple cell types and multiple lipid formulations, suggesting broad applicability.
• The mechanism of enhancement was identified as promotion of clathrin-independent carrier-mediated endocytosis.

AAS promoted clathrin-independent carrier-mediated endocytosis as the mechanism by which it enhanced LNP uptake and mRNA expression.

• The endocytic pathway identified was clathrin-independent carrier-mediated endocytosis.
• This mechanistic finding was established using the in vitro system.
• This pathway was distinct from classical clathrin-mediated endocytosis.

Delivery of mRNA by LNPs coadministered with AAS by multiple routes enhanced in vivo mRNA expression in preclinical models.

• Multiple routes of administration were tested in preclinical (animal) models.
• In vivo mRNA expression was enhanced relative to LNP administration alone.
• The finding suggests the AAS benefit translates from in vitro to in vivo settings.

Delivery of growth hormone-encoding mRNA by LNPs with AAS coadministration improved liver growth hormone expression and therapeutic outcomes in a model of inflammatory liver damage.

• mRNA encoded growth hormone and was delivered via LNPs.
• AAS was coadministered with the LNPs.
• Improved liver growth hormone expression was observed.
• Therapeutic outcomes were improved in an inflammatory liver damage preclinical model.

Intratracheal delivery of gene editing materials by LNP with AAS increased lung-targeted in vivo gene editing efficiency compared with LNP alone.

• The route of administration was intratracheal.
• Gene editing materials (not specified further in the abstract) were delivered via LNP.
• AAS coadministration increased lung-targeted gene editing efficiency.
• The comparison was made directly against LNP alone without AAS.