Ionizable Lipid Nanoparticles for Large RNA Delivery and Endosomal Escape
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Solution Overview
Problem
Current lipid nanoparticles (LNPs) are inefficient in delivering large RNA constructs like self-amplifying RNA (saRNA) due to poor encapsulation and sub-optimal in vivo delivery, and they often result in toxicity and nonspecific interactions with biological fluids.
Innovation Solution
Development of ionizable lipid-like compounds with branched alkyl side chains and multiple amide or ester functional groups, formulated into lipid nanoparticles (LNPs) that protect saRNA from nucleases and facilitate cellular uptake by maintaining a neutral surface charge at physiological pH and protonating at acidic pH for endosomal escape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cationic lipids with permanent positive charge are used in LNPs, then RNA encapsulation is improved, but toxicity increases and nonspecific interactions occur
Solution Approach 1:
The patent applies parameter changes by transitioning from lipids with permanent positive charge to ionizable lipids whose charge state changes with pH. At physiological pH (7.4), the ionizable lipids are neutral, reducing toxicity and nonspecific interactions. Upon endosomal acidification (pH 5-6), they become positively charged to facilitate RNA release. This dynamic charge parameter change resolves the contradiction between effective RNA encapsulation and reduced toxicity.
Solution Approach 2:
The invention employs dynamics by using ionizable lipids that dynamically change their charge state in response to environmental pH changes. The lipids remain neutral in circulation (reducing harmful interactions) and become positively charged only in the acidic endosomal environment (enabling RNA release). This temporal and spatial dynamics allows the system to optimize both safety and efficacy at different stages of delivery.
2Productivity
If LNPs are designed for conventional mRNA delivery, then delivery efficiency is improved, but they are inefficient for large RNA constructs like saRNA
Solution Approach 1:
The patent applies universality by designing ionizable lipid formulations that can effectively deliver both conventional mRNA and large self-amplifying RNA constructs. The ionizable lipid structure and formulation parameters are optimized to accommodate varying RNA sizes and complexities, making the delivery system universally applicable across different RNA therapeutic types while maintaining high delivery efficiency for each.
3Quantity of substance
If saRNA is used to reduce RNA concentration, then therapeutic dose is reduced, but delivery complexity increases due to larger molecule size
Solution Approach 1:
The patent applies parameter changes by optimizing the ionizable lipid:RNA ratio and formulation parameters specifically for large saRNA constructs. The ionizable lipid composition and pH-responsive properties are tuned to effectively encapsulate and deliver the larger RNA molecules, transforming the delivery system parameters to match the increased complexity of saRNA while maintaining reduced therapeutic dosing.
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 novel LNPs efficiently encapsulate and deliver large RNA constructs, such as saRNA, with improved tolerability and reduced toxicity, enhancing intracellular delivery and expression.
Implementation Method 1
Lipids or lipid-like compounds according to the invention, will be protonated at low pH, but will display a relatively neutral surface charge at physiological pH
Implementation Method 2
Acidification leads to the disruption of the membrane and the endosomal escape of the RNA
Implementation Method 3
The encapsulation of negatively charged RNA in LNPs largely depends on the interaction with positively charged amino lipids
Data Source
Figure 1A~1B
AI summary
The current invention relates to ionizable lipid-like compound according to Formula (I) or pharmaceutically acceptable salt, tautomer, or stereoisomer thereof. The present invention also provides a lipid nanoparticle comprising an ionizable lipid-like compound according to Formula (I) and one or more RNA molecules, as well as a pharmaceutical composition or vaccine, comprising such lipid nanoparticles.