Device-Mediated Gastrointestinal Delivery of mRNA-LNPs: Expression and Biodistribution in Murine and Porcine Models

Study Background and Research Question

Messenger RNA (mRNA) therapeutics have rapidly advanced as promising tools for vaccination and treatment of various diseases, including cancer, diabetes, and infectious diseases. Traditionally, mRNA-lipid nanoparticles (mRNA-LNPs) are administered via intravenous (IV), intramuscular (IM), or subcutaneous (SC) injections, which typically require trained personnel and are associated with discomfort and reduced patient compliance. The quest for less invasive, self-administered delivery methods has spurred interest in ingestible devices capable of delivering therapeutics directly to the gastrointestinal (GI) tract. However, the expression kinetics and biodistribution profiles of mRNA-LNPs delivered through GI wall injection remain largely unexplored. The central research question of the referenced study is: Can device-mediated delivery of mRNA-LNPs into the GI wall achieve effective and distinct expression and biodistribution compared to standard injection routes? (reference study).

Key Innovation from the Reference Study

The primary innovation of this study lies in the use of autonomous, ingestible microjet devices (MiDe) to deliver mRNA-LNPs directly into the submucosal layer of the stomach and intestinal wall in live animal models. This approach enables needle-free, targeted administration, potentially allowing patients to self-administer mRNA therapies orally—thereby improving accessibility and compliance. Crucially, the study systematically compares the pharmacokinetic (PK) and biodistribution profiles of GI wall delivery to those of IM, IV, and SC injections, providing foundational data for the translational development of oral mRNA drugs and vaccines.

Methods and Experimental Design Insights

The research deployed a jet injection technique using a hand-held microjet device equipped with a fine (254 μm) nozzle, capable of generating a pressurized liquid stream to penetrate GI tissue. Cryo-transmission electron microscopy (Cryo-TEM) was used to evaluate the structural integrity of mRNA-LNPs before and after jetting. Physical properties such as nanoparticle size, polydispersity index (PDI), surface charge, and encapsulation efficiency were assessed pre- and post-jetting. Functional expression was measured using a firefly luciferase reporter mRNA—a well-established bioluminescent reporter mRNA—in HEK293T cells following transfection with jetted and non-jetted samples. In vivo, both mice and minipigs received mRNA-LNPs delivered into the gastric and intestinal walls, and subsequent biodistribution and expression were quantified using bioluminescence imaging and plasma assays (reference study).

Protocol Parameters

• mRNA-LNP formulation: Standard LNP encapsulation of firefly luciferase mRNA; maintain encapsulation efficiency above 90%.
• Jetting device settings: 8 bar backing pressure; 254 μm nozzle; volumes compatible with animal model GI wall thickness.
• Animal models: Use both murine (mice) and porcine (minipig) models to assess cross-species applicability.
• Reporter assay: Quantify luciferase activity in target tissues and plasma at multiple timepoints post-delivery for expression kinetics.
• Comparative controls: Include IM, IV, and SC injection groups for direct comparison of biodistribution.

Core Findings and Why They Matter

The study found that mRNA-LNPs delivered by microjet injection into the stomach and intestinal walls retained their physical and functional integrity, as evidenced by unchanged nanoparticle size, surface characteristics, and high encapsulation efficiency after jetting. Luciferase expression assays revealed robust gene expression following GI wall delivery, with bioluminescent signals detected in both local GI tissues and distal organs, including plasma and lymph nodes. Notably, the biodistribution profiles achieved through GI wall injection were distinct from those of conventional IM and IV routes—showing broader systemic exposure and potential for improved immunogenicity in vaccination settings (reference study).

This work substantiates the feasibility of device-mediated oral mRNA delivery, supporting the development of pain-free, self-administered mRNA therapeutics. It also suggests that tailored GI wall delivery may offer unique advantages for vaccines requiring both local and systemic immune activation.

Comparison with Existing Internal Articles

Several recent reviews have highlighted the advantages of chemically modified reporter mRNAs, such as Firefly Luciferase mRNA (ARCA, 5mCTP, ΨUTP), in enhancing stability, immune evasion, and translation efficiency in gene expression assays (mechanistic insight). The current study's use of firefly luciferase mRNA-LNPs aligns with these mechanistic strategies, demonstrating that even under the mechanical stress of jet injection, such modified mRNAs maintain their functional performance. Internal analyses have previously discussed the translation of mRNA-LNP advances into higher-sensitivity cell viability assays and in vivo imaging (internal review), and the present study extends these findings to the context of device-mediated GI delivery. It reinforces the importance of robust, modified reporter mRNAs in evaluating new drug delivery modalities and optimizing workflow reproducibility.

Limitations and Transferability

Despite these promising results, several limitations should be considered. First, while murine and porcine models offer valuable translational insight, human GI tract anatomy and immune responses may differ, potentially affecting both delivery efficiency and biodistribution. Second, the study focused on a single reporter mRNA; further validation with therapeutic mRNAs encoding clinically relevant proteins is warranted. Third, the long-term safety of repeated GI wall injections, as well as patient acceptability of ingestible devices, remains to be established through clinical trials.

Transferability to other mRNA therapeutics will require careful consideration of formulation compatibility, dosing strategies, and regulatory requirements. However, the technical feasibility demonstrated here positions microjet devices as a viable alternative to injection-based mRNA delivery, particularly for vaccines and systemic gene therapies.

Why this cross-domain matters, maturity, and limitations

This study bridges the domains of drug delivery engineering and molecular therapeutics, illustrating how advances in device design can directly impact the translation of nucleic acid medicines. By validating bioluminescent reporter mRNA as both a functional readout and a delivery platform, the research supports broader adoption of integrated device-mRNA workflows for preclinical and translational studies. However, as the technology matures, further work is needed to optimize device ergonomics, mRNA payload versatility, and real-world deployment in diverse patient populations.

Research Support Resources

Researchers developing or benchmarking novel gene expression assay and in vivo imaging workflows may benefit from standardized, highly modified reporter mRNAs. Firefly Luciferase mRNA (ARCA, 5mCTP, ΨUTP) (SKU R1005) provides enhanced stability, reduced innate immune activation, and high translational efficiency, making it a practical choice for validating delivery, expression, and biodistribution in preclinical models. Used as a control or benchmark reagent, it complements studies of mRNA-LNP delivery modalities, including those leveraging ingestible microjet devices.