Self-Amplifying mRNA–LNP Delivery for Lower-Dose Antigen Expression
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Solution Overview
Problem
Existing mRNA vaccines face challenges in achieving adequate antigen expression and immunomodulation due to the need for large doses or repeated administrations, which can elicit undesirable immune responses and reduce efficacy, while delivery of biologically active agents is hindered by the properties of RNA, including size and instability.
Innovation Solution
Development of novel ionizable lipids and nanoparticle compositions for improved delivery of self-amplifying mRNA (sa-mRNA) to increase transfection efficiency and reduce cytotoxicity, using formulations with specific molar ratios of ionizable, helper, cholesterol, and PEG-lipids, along with modified nucleic acids to enhance transcription and reduce immunogenicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If large doses of mRNA vaccines are administered, then adequate antigen expression is achieved, but undesirable immune responses are elicited
Solution Approach 1:
The patent modifies the chemical structure of lipids in the LNP formulation, specifically using ionizable lipids with modified head groups and tail chains. This changes the physical and chemical parameters of the delivery vehicle to improve cellular uptake and reduce immunogenicity, allowing effective antigen expression at lower mRNA doses
Solution Approach 2:
The patent introduces ionizable lipids as intermediary components that mediate between the mRNA payload and the cellular environment. These lipids facilitate endosomal escape and cellular uptake while modulating the immune response, acting as a buffer that reduces harmful effects at lower doses
2Reliability
If repeated administrations of mRNA vaccines are given, then adequate immune response is achieved, but subsequent administration becomes less effective
Solution Approach 1:
The patent employs self-amplifying mRNA that can replicate within cells, creating a continuous production of antigen without requiring repeated external administrations. This maintains reliable immune stimulation over time while avoiding the diminishing efficacy associated with repeated dosing
Solution Approach 2:
The self-amplifying mRNA mechanism allows the vaccine to amplify itself within the host cell, generating multiple copies of the antigen without continuous external input. This self-sustaining mechanism maintains efficacy over time without requiring repeated administrations
3Productivity
If self-amplifying mRNA is used to increase transcript copies, then antigen expression is improved, but interferon responses and cytotoxicity increase
Solution Approach 1:
The patent applies local modifications to specific regions of the mRNA molecule, including changes in the 5' UTR, coding sequence, and 3' UTR. These localized alterations optimize translation efficiency and reduce overall interferon stimulation, allowing high transcript copies without excessive cytotoxicity
Solution Approach 2:
The patent creates a composite system combining modified mRNA with ionizable lipid LNPs. This composite formulation delivers the mRNA to specific cell types with enhanced efficiency while the lipid composition modulates the immune response, reducing cytotoxicity despite high transcript production
4Ease of operation
If conventional LNPs are used for delivery, then some cell uptake is achieved, but transfection efficiency is insufficient and cytotoxicity occurs
Solution Approach 1:
The patent systematically modifies lipid parameters including head group composition, tail chain length and saturation, and ionization pH. These parameter changes optimize the balance between cellular uptake and transfection efficiency while minimizing cytotoxicity
Solution Approach 2:
The patent employs ionizable lipids that dynamically change their charge state based on pH. At physiological pH, they remain neutral for stable circulation, then become protonated in the acidic endosome to facilitate membrane disruption and cargo release, providing dynamic control over delivery efficiency
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances antigen expression and immunomodulation with lower doses, improves delivery efficiency, and reduces safety concerns, resulting in increased copy numbers of mRNA transcripts and controlled immune responses.
Implementation Method 1
Ionizable lipids, one component of LNPs, are believed to play key role in uptake of LNPs by cells and the release of LNPs from the endosome
Data Source
AI summary
Lipid nanoparticle (LNP) encapsulating self-amplifying mRNA, compositions, and methods of using the novel nucleic acid constructs and compositions are disclosed. LNP constructs include novel ionizable lipid. Novel sa-mRNA constructs encode a modified SARS-COV-2 spike protein, wherein the polynucleotide has been truncated to not include nucleotides encoding a SARS-COV-2 transmembrane domain and short cytosolic domain amino acids and immunomodulators. Sa-mRNAs are useful in for use as a therapeutic, diagnostic and/or prophylactic agent to mammalian cells or organs.