All Encapsulated is Not Expressed: Ribosomal Engagement Shaped by LNP Morphology & RNA Integrity

Lipid nanoparticle (LNP)-based delivery of mRNA therapeutics has revolutionized vaccine and therapeutic development, yet not all encapsulated mRNA leads to successful protein translation. This presentation explores the critical determinants of translational efficiency, emphasizing that ribosomal engagement is shaped not only by mRNA encapsulation but also by LNP morphology and RNA integrity. Using eRibo Pro technology, ribosome occupancy and mRNA release were quantified to assess the impact of formulation variables and stress conditions.

Key findings demonstrate that LNP size, shape, and heterogeneity significantly influence endosomal escape and ribosome binding. External stresses such as thermal exposure, agitation, and lyophilization compromise LNP integrity, reducing encapsulation efficiency and degrading RNA, which in turn impairs translation. Despite these challenges, translation efficiency remains robust across different mRNA types and LNP formulations, highlighting the flexibility of design strategies.

The study underscores that encapsulation alone is not predictive of expression. Instead, a holistic understanding of molecular packing, RNA integrity, and LNP architecture is essential for optimizing mRNA translation. These insights inform the rational design of next-generation mRNA therapeutics with improved efficacy and resilience.