Methods: We engineered an orally delivered (OrD) LNPs by incorporating a cationic lipid into the base LNP structure to enhance stability and efficacy. This formulation was adeptly designed to accommodate various nucleic acids—siRNA, miRNA, and mRNA—highlighting its broad applicability. The formulation's performance was evaluated in biorelevant media that simulated the gastrointestinal tract (GIT) environment, including bile salts, buffers, and mucin. To assess its therapeutic efficacy, we utilized an LPS-induced inflammatory model in macrophages and further investigated its potential in an in vivo model of acute colitis.
Results: The LNPs demonstrated improved stability under fasted gastrointestinal (GI) conditions with an increased proportion of cationic lipid, although in vitro efficacy diminished at higher cationic lipid levels, highlighting the crucial role of ionizable lipids. The optimal OrD LNP formulation contained 20% cationic lipid. Confocal imaging and flow cytometry validated cellular uptake in both epithelial and macrophage cell lines. In vivo studies employing siRNA and mRNA payloads effectively demonstrated gene silencing and expression, respectively, within the gastrointestinal tract. While the OrD LNP showed promising results in an LPS-induced inflammatory model with siRNA and miRNA, efficacy was limited in an acute colitis model. However, stem-loop PCR confirmed successful intestinal transport of the nucleic acid.
Conclusion: The results support the use of OrD LNP technology for nucleic acid delivery to the GIT in both naive and diseased models. This method offers a non-invasive alternative to injectable therapies, potentially revolutionizing GI disorder treatment. Future research will focus on clinical platform optimization to expand RNA-based treatment applications by investigating in different disease models.
Acknowledgements: All work described in this abstract was funded by Takeda Development Center Americas in support of Northeastern University’s Experiential PhD program
References: Suri, K., Pfeifer, L., Cvet, D. et al. Oral delivery of stabilized lipid nanoparticles for nucleic acid therapeutics. Drug Deliv. and Transl. Res. (2024). https://doi.org/10.1007/s13346-024-01709-4