Lipid Particles for Nucleic Acid Delivery with Low Cytotoxicity

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Solution Overview

Problem

Current cationic lipid-based carriers for nucleic acid delivery exhibit high cytotoxicity and insufficient release of nucleic acids in target cells, limiting their effectiveness as safe and efficient delivery agents.

Innovation Solution

Lipid particles comprising a compound with specific alkyl groups, sterol, and a polyethylene glycol chain, which facilitate low cytotoxicity and efficient nucleic acid release by forming stable complexes and promoting membrane fusion for targeted delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cationic lipid-based carriers are used for nucleic acid delivery, then nucleic acid delivery capability is improved, but cytotoxicity increases

Engineering Contradiction:
Improvenucleic acid delivery capabilityVSAvoidcytotoxicity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical structure of cationic lipids by introducing specific substituents (aromatic rings, heteroatoms, varying alkyl chain lengths) to adjust the balance between positive charge density and hydrophobicity. This parameter optimization reduces cytotoxicity while preserving nucleic acid binding and delivery capabilities.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses composite lipid formulations combining multiple lipid components with different properties (cationic lipids for nucleic acid binding, neutral lipids for membrane fusion, PEGylated lipids for stability). This composite approach distributes functions across components, reducing the cytotoxic burden on any single component while maintaining overall delivery efficacy.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If cationic lipid carriers are used to hold nucleic acids, then nucleic acid stability outside cells is improved, but nucleic acid release in target cells is insufficient

Engineering Contradiction:
Improvenucleic acid stability outside cellsVSAvoidnucleic acid release in target cells
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The lipid carriers are designed to dynamically change properties in response to cellular environment cues. The lipids undergo phase transitions or structural reorganization upon endosomal acidification or membrane contact, switching from a stable nucleic acid-binding state extracellularly to a membrane-fusogenic state intracellularly, enabling controlled release.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent incorporates lipids with pH-sensitive or membrane-interaction-sensitive properties that change their conformational state or binding affinity under different conditions. This parameter change allows the carrier to maintain tight nucleic acid binding during circulation but facilitate release upon cellular uptake.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If amphoteric liposomes are used to reduce cytotoxicity, then cytotoxicity is reduced, but practical readiness and delivery efficiency are insufficient

Engineering Contradiction:
ImprovecytotoxicityVSAvoiddelivery efficiency
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent employs lipids with localized functional regions: cationic headgroups for nucleic acid binding, hydrophobic tails for membrane interaction, and PEGylated regions for steric stabilization. This local quality differentiation allows each region to optimize its function while the overall structure maintains low cytotoxicity and high delivery efficiency.

Inventive Principle:
Principle #3Local quality

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 described lipid particles demonstrate low cytotoxicity and efficient nucleic acid release in target cells, enhancing drug efficacy and safety for nucleic acid delivery applications.

Implementation Method 1

A cationic carrier which can hold nucleic acids through an electrostatic interaction is used as the non-viral carrier since nucleic acids are anionic

Methodology Applied
Scientific EffectElectrostatic interaction: Electrostatics

Implementation Method 2

can promptly release nucleic acids in cytoplasm after escaping from endosome

Methodology Applied
Scientific EffectMembrane fusion:

Data Source

PatentEP3170503B1Lipid particles and nucleic acid delivery carrier
Publication Date: 2018.06.27 FUJIFILM CORP
  • EP3170503B1 patent drawingFigure 1~2
  • EP3170503B1 patent drawingFigure 3
  • EP3170503B1 patent drawingFigure 4

AI summary

An object of the present invention is to provide lipid particles which have low cytotoxicity, can stably hold nucleic acid molecules outside cells, and can promptly release nucleic acids in cytoplasm after escaping from endosome, and a nucleic acid delivery carrier. According to the present invention, there are provided lipid particles containing a compound represented by the following General Formula (1), sterol, at least one lipid selected from the group consisting of a neutral lipid and a lipid having a polyethylene glycol chain, and nucleic acids, and a nucleic acid delivery carrier. In the formula, R1 and R2 are the same as or different from each other, and are alkyl groups having 10 to 22 carbon atoms.