Low Molecular Weight Cationic Lipids for siRNA Delivery

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Solution Overview

Problem

Traditional cationic lipids used for siRNA delivery, such as CLinDMA and DLinDMA, suffer from non-optimal delivery efficiency and liver toxicity at higher doses, limiting their effectiveness and tolerability in vivo.

Innovation Solution

A method for preparing low molecular weight cationic lipids with a short lipid chain is developed, enhancing the efficiency and reducing liver toxicity by forming lipid nanoparticles with oligonucleotides, specifically siRNA, for improved cellular uptake and endosomal escape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional cationic lipids (CLinDMA, DLinDMA) are used for siRNA delivery, then delivery capability is achieved, but liver toxicity increases at higher doses

Engineering Contradiction:
Improvedelivery efficiencyVSAvoidliver toxicity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the molecular structure of cationic lipids by changing parameters such as reducing the number of carbon atoms in the lipid chain (from typical 16-24 carbons to 10-15 carbons), adjusting the degree of saturation, and modifying the head group composition. These parameter changes result in lower molecular weight lipids that achieve effective siRNA delivery while reducing accumulation in the liver and associated toxicity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention segments the lipid molecule into distinct functional regions with optimized lengths and compositions - a shorter hydrophobic tail segment (10-15 carbons) and a specifically designed head group segment. This segmentation allows each part to perform its function optimally while reducing overall molecular size and liver accumulation.

Inventive Principle:
Principle #1Segmentation

2Productivity

If higher doses of traditional cationic lipids are administered, then delivery efficiency improves, but liver toxicity worsens

Engineering Contradiction:
Improvedelivery efficiencyVSAvoidliver toxicity
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

By changing the molecular parameters of the cationic lipid (reducing chain length to 10-15 carbons, adjusting saturation level), the patent achieves a formulation where effective delivery is obtained at lower doses, eliminating the need to increase dose to improve productivity while avoiding the associated toxicity increase.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If cationic lipids with longer chains are used, then membrane stability improves, but cellular uptake efficiency decreases

Engineering Contradiction:
Improvemembrane stabilityVSAvoidcellular uptake efficiency
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent optimizes the parameter of lipid chain length to a specific range (10-15 carbons) that balances membrane stability requirements with cellular uptake efficiency. This optimized parameter value prevents the degradation of membrane stability that occurs with longer chains while avoiding the reduction in uptake efficiency associated with shorter chains.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3943114B1Novel low molecular weight cationic lipids for oligonucleotide delivery
Publication Date: 2024.08.07 SIRNA THERAPEUTICS INC
  • EP3943114B1 patent drawingFigure 1~2
  • EP3943114B1 patent drawingFigure 3~4
  • EP3943114B1 patent drawingFigure 5~6

AI summary

The present invention relates to methods for the preparation of specific cationic lipids, as well as compounds used in the same.