Multi-Tail Ionizable Lipids for Low-Toxicity RNA Delivery
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Solution Overview
Problem
Existing nucleic acid delivery systems face challenges such as low efficiency, high toxicity, and poor targeting, particularly for RNA molecules due to their inherent negative charge and instability, necessitating a safe and stable delivery system to protect RNA from degradation and enhance cellular uptake.
Innovation Solution
A multi-tail type ionizable lipid is synthesized through a simple and efficient chemical process, featuring a tertiary or secondary amino group head, which self-assembles into lipid nanoparticles to deliver nucleic acids, utilizing a chemical structure with ionizable head groups, linking groups, and hydrophobic tails, allowing for pH-dependent charge changes and enhanced endosomal escape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional cationic liposomes are used for nucleic acid delivery, then transfection efficiency is improved, but cellular toxicity increases significantly
Solution Approach 1:
The patent applies parameter changes by using ionizable lipids that change their charge state based on pH. At physiological pH (7.4), the lipids are neutral, reducing toxicity. In the acidic endosomal environment (pH 5.0-6.0), they become positively charged to facilitate membrane disruption and escape, thus resolving the contradiction between transfection efficiency and cellular toxicity
Solution Approach 2:
The invention employs dynamic pH-responsive charge transformation of the ionizable lipid molecules. The lipids dynamically switch from neutral at blood pH to positive at endosomal pH, enabling the system to adapt its properties to different physiological environments and achieve both low systemic toxicity and high endosomal escape efficiency
2Device complexity
If RNA molecules are delivered directly without protection, then delivery simplicity is maintained, but RNA stability decreases due to degradation
Solution Approach 1:
The patent uses lipid nanoparticles with flexible lipid bilayer structures to encapsulate and protect RNA molecules. The lipid shell provides physical protection against degradation while maintaining a relatively simple delivery system architecture, thus resolving the contradiction between simplicity and stability
3Object-affected harmful factors
If neutral lipids are used at physiological pH, then biocompatibility is improved, but endosomal escape capability deteriorates
Solution Approach 1:
The invention uses ionizable lipids that undergo parameter changes in response to pH. At physiological pH, they remain neutral for biocompatibility, but in the acidic endosome, they protonate to become positive, enabling membrane disruption and escape. This pH-dependent parameter change resolves the contradiction between biocompatibility and escape capability
4Ease of manufacture
If single-tail lipids are used, then synthesis simplicity is maintained, but delivery efficiency decreases due to insufficient conical structure formation
Solution Approach 1:
The patent employs multi-tail lipids with asymmetric structures that form more effective conical shapes compared to symmetric single-tail lipids. The asymmetric multi-tail configuration enhances membrane curvature and conical structure formation, improving delivery efficiency while maintaining reasonable synthesis complexity
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 multi-tail type ionizable lipid achieves high delivery efficiency with low toxicity, facilitating rapid RNA release and improved transfection effects by forming conical structures that destabilize endosomes, thus enhancing the stability and circulation time of nucleic acid drugs.
Implementation Method 1
The head group of this ionizable lipid is a tertiary amino group or a secondary amino group, which can obtain a proton at acidic pH and carry a positive charge
Implementation Method 2
A multi-tail type ionizable lipid is synthesized through a simple and efficient chemical process, featuring a tertiary or secondary amino group head, which self-assembles into lipid nanoparticles to deliver nucleic acids
Implementation Method 3
facilitating rapid RNA release and improved transfection effects by forming conical structures that destabilize endosomes
Data Source
AI summary
A multi-tail type ionizable lipid, a preparation method therefor and the use thereof are disclosed. The structural formula of the multi-tail type ionizable lipid of the present invention is as follows,wherein R1 and R2 are the same or different, and each is hydrogen or an alkyl chain or an alkyl ring consisting of 1 to 6 carbons, or R1 and R2 together form a nitrogen-containing alkyl ring; L1 and L2 are the same or different, and each is an alkyl chain or an unsaturated hydrocarbyl group consisting of 1 to 6 carbons in length; and R is an alkyl group, an alkyl ring, an unsaturated hydrocarbyl group, or a heterohydrocarbyl group; and n=1 to 6, m1=1 to 15, m2=1 to 15, and x=0 to 5.