Activated PACE Terpolymers for Gene Delivery

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Solution Overview

Problem

Current non-viral gene delivery methods, such as cationic lipid and polymer-based systems, face challenges with stability in physiological fluids, toxicity, and limited ability to efficiently and safely deliver DNA and nucleic acids, especially across the blood-brain barrier and to the central nervous system.

Innovation Solution

Development of activated poly(amine co ester) (PACE) terpolymers, specifically synthesized by combining 15-pentadecanolide, diethanolamine, and diethyl sebacate, which are chemically modified through hydrolysis to create low molecular weight polymers with tunable hydrophobicity, enhancing stability and reducing toxicity for efficient gene delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cationic polymers are used to form polyplexes with DNA for gene delivery, then transfection efficiency is improved, but stability in physiological fluids deteriorates due to aggregation and clearance by the reticuloendothelial system

Engineering Contradiction:
Improvetransfection efficiencyVSAvoidstability in physiological fluids
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by modifying the polymer's molecular weight, charge density, and chemical composition to create PACE polymers with optimized properties. The polymers are designed with specific molecular weights (5-25 kDa) and controlled charge densities to maintain stability in physiological fluids while preserving transfection efficiency, resolving the contradiction between these two parameters.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by creating copolymer structures with multiple functional units within the PACE polymer chain. These composite structures combine cationic segments for DNA binding with hydrophilic and biodegradable segments, enabling the polyplexes to remain stable in serum while maintaining high transfection efficiency.

Inventive Principle:
Principle #40Composite materials

2Productivity

If cationic polymers with excess charge are used to form polyplexes, then DNA condensation and cellular uptake are improved, but toxicity increases substantially limiting clinical applicability

Engineering Contradiction:
ImproveDNA condensation efficiencyVSAvoidtoxicity
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by precisely controlling the charge density and molecular weight of the PACE polymers. The polymers are designed with optimized charge densities that provide sufficient DNA condensation capability while minimizing cytotoxic effects, thereby resolving the contradiction between condensation efficiency and toxicity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by creating polymers with spatially distributed functional groups - cationic segments localized for DNA binding and condensation, while hydrophilic and biocompatible segments are distributed throughout the chain to reduce toxicity. This local differentiation of properties allows the polymer to simultaneously achieve high condensation efficiency and low toxicity.

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If high molecular weight polymers are used for gene delivery, then DNA complexation stability is improved, but ability to cross the blood-brain barrier and deliver to central nervous system deteriorates

Engineering Contradiction:
Improvecomplexation stabilityVSAvoidability to cross blood-brain barrier
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by optimizing the molecular weight of PACE polymers to a specific range (5-25 kDa) that balances complexation stability with blood-brain barrier penetration capability. This controlled molecular weight range allows the polyplexes to maintain structural integrity while being small enough to cross the blood-brain barrier and deliver genes to the central nervous system.

Inventive Principle:
Principle #35Parameter changes

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 activated PACE terpolymers demonstrate improved stability, reduced toxicity, and enhanced transfection efficiency comparable to commercial vectors, enabling effective delivery of DNA and mRNA both in vitro and in vivo, including across the blood-brain barrier.

Implementation Method 1

exposing the polymer to conditions such that one or more backbone esters are hydrolyzed, thereby exposing one or more activated end group(s)

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

Both cationic lipid and cationic polymer systems deliver genes by forming condensed complexes with negatively charged DNA through electrostatic interactions

Methodology Applied
Scientific EffectElectrostatic interactions: Electrostatics

Data Source

PatentEP3423106B1Biodegradable activated polymers for therapeutic delivery
Publication Date: 2022.07.27 ALEXION PHARMACEUTICALS INC
  • EP3423106B1 patent drawingFigure 1
  • EP3423106B1 patent drawingFigure 2A~2C
  • EP3423106B1 patent drawingFigure 3A

AI summary

Activated polymers comprising one or more backbone ester(s) are disclosed. In particular, activated poly(amine-co-ester) (aPACE) terpolymers and methods of making and using these aPACE terpolymers are disclosed. These aPACE terpolymers can be used to safely and efficiently deliver biomolecules, in particular nucleic acids, to cells, both in vitro and in vivo. Methods for making activated polymers are also provided. Furthermore, methods for delivering mRNA and methods of gene therapy using activated polymers, in vitro and/or in vivo are further disclosed.