Targeted Gastrointestinal Delivery of mRNA Lipid Nanoparticles Enables Systemic Vaccination and Glucagon-like Peptide-1 Metabolic Therapy

Abstract

Lipid nanoparticles (LNPs) administered parenterally often show poor localization to multiple tissue types, including the pancreas and gastrointestinal (GI) tract. Furthermore, patients typically prefer orally administered drugs to those that are given parenterally. We therefore investigated whether GI LNP administration to buccal, gastric, small intestinal, colonic, and rectal submucosal tissues could simultaneously circumvent parenteral administration while enhancing LNP delivery to previously inaccessible locations. We found that, in addition to local targeting, gastric LNP administration achieved an order of magnitude greater pancreas delivery in rodents than intravenous administration. Gastric dosing of glucagon-like peptide-1 mRNA also improved blood glucose regulation in mice compared with phosphate-buffered saline controls. Additionally, we found that buccal LNP administration targeted local and lymphatic tissues. Furthermore, dosing mice with ovalbumin mRNA resulted in equivalent immunoglobulin G blood titers to those of intramuscular delivery. These results suggest that GI administration can reprogram LNP biodistribution, expanding therapeutic opportunities for both local and systemic nucleic acid delivery.

Introduction

Therapeutic nucleic acids feature in over 20 U.S. Food and Drug Administration-approved products. (1−3) However, messenger RNA (mRNA) drug products have been limited to intramuscularly administered vaccines, and short interfering RNA (siRNA) products have been limited to intravenous delivery for liver diseases. Nonliver delivery remains challenging, yet nucleic acids show promise in treating preclinical models of gastrointestinal diseases, including gastroesophageal cancer, gastric carcinoma, and ulcerative colitis, as well as pancreatic diseases such as cancer and diabetes. (4−11) To improve nonliver delivery, laboratories alter lipid nanoparticle (LNP) chemistry by adding active targeting ligands or permanently charged helper lipids. (12−16) An alternative strategy involves altering the administration route. Scientists have reported improved lung delivery using nebulization, (17) improved lymphatic delivery using subcutaneous or intramuscular administration, (18, 19) and improved pancreas delivery via intraperitoneal administration (20) yet it remains unclear whether other delivery routes alter LNP tropism.

Given the advent of new technologies for the gastrointestinal (GI) delivery of biologics (21−25) and evidence that patients prefer oral alternatives to parenteral administration, (26, 27) we found this question compelling. Specifically, scientists have reported approaches to avoid the harsh environment and diffusional barriers of the GI tract, (28) including endoscopic injections, (24) miniaturized ingestible microneedle pills (22) and patches, (29) jet injection pills, (4, 25) ultrasound mediated enemas, (30) and novel formulations. (31−33) All of these have generated data consistent with local endoluminal and buccal nucleic acid uptake. However, it remains unclear how altering the GI-related route of administration affects delivery systemically. The on- and off-target delivery ratios as a function of administration route are especially important given that unwanted liver delivery is an established challenge in the field of nucleic acid therapeutics.

Here, we systematically investigated LNP-mRNA delivery to the submucosa of clinically relevant GI organs, including buccal, gastric, small intestine, colonic, and rectal tissues. We found that the site of administration dramatically alters the biodistribution of translated proteins, unlocking opportunities for both local and systemic targets. For example, after submucosal buccal LNP injections, we observed noticeable delivery to local buccal tissue as well as inguinal lymph nodes. Furthermore, delivering an ovalbumin mRNA cargo to the buccal regions resulted in systemic immunoglobulin G (IgG) blood serum titers. Buccal delivery matched intramuscular vaccination IgG titers at equivalent 1 μg doses and retained measurable systemic IgG responses at a 10-fold lower dose, where intramuscular administration failed to generate an immune response. Separately, we discovered that gastric delivery resulted in significantly higher uptake locally as well as in the pancreas compared to intravenous administration. This delivery improvement was coupled with significantly lower uptake in other organs such as the liver, lungs, heart, and spleen. Combining these administration routes with formulation modifications, such as adding a cationic helper lipid, further improved pancreas targeting. To demonstrate the metabolic therapeutic potential of gastric nucleic acid administration, we delivered a glucagon-like peptide-1 (GLP-1) mRNA cargo injection to the gastric submucosa and noted that it resulted in improved blood glucose control in mice compared to controls. Our studies highlight that optimizing GI delivery routes and LNP composition may lead to differentiated LNP tropism as well as provide meaningful therapeutic potential in vivo.

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Lipid Nanoparticle Formation

LNPs carrying aNLuc and Cre mRNA were formulated using the NanoAssemblr Ignite (Precision NanoSystems). SM-102 was purchased from Organix Inc., and cholesterol, poly(ethylene glycol) (PEG) lipids, and helper lipids were purchased from Avanti Lipids. Aqueous (25 mM acetate) and organic (100% ethanol) phases were mixed at a flow rate ratio of 3:1 and a total flow rate of 12 mL min–1. An anionic LNP containing DOPA was not successfully formulated under the same conditions. Stabilizing this formulation would require modification of other core components, such as alternative lipid ratios and different starting buffers. For example, DOPA is not soluble in ethanol but is in a chloroform-containing solution. Making these changes would introduce confounding variables when isolating the effect of the surface charge. Therefore, we focused our charge-based comparisons on the LNPneut and LNPcat.

Abdulraouf M. Abbas, Ramy Ghanim, Sebastian Rudden, David Schultz, Bora Jang, Avraham Shakked, Hyejin Kim, James E. Dahlman, Alex Abramson; Targeted Gastrointestinal Delivery of mRNA Lipid Nanoparticles Enables Systemic Vaccination and Glucagon-like Peptide-1 Metabolic Therapy. ACS Nano 2026; https://doi.org/10.1021/acsnano.5c18549

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