Polyelectrolyte Cryopreservation of EVs Without DMSO Toxicity

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Solution Overview

Problem

Current methods for cryopreserving extracellular vesicles (EVs) result in structural changes and degradation due to ice crystal formation and osmotic pressure changes, leading to reduced biological activity, and existing cryoprotectants like DMSO are toxic and require complex post-thaw procedures.

Innovation Solution

The use of polyelectrolytes, including modified polymers such as dextran derivatives and synthetic polyelectrolytes, to coat and stabilize EVs during freezing, maintaining structural integrity and biological activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If conventional cryoprotectants like DMSO are used to preserve EVs during freezing, then structural integrity is improved, but toxicity increases and complex post-thaw procedures are required

Engineering Contradiction:

Improvestructural integrity of EVsVSAvoidtoxicity of cryoprotectants

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent uses polyelectrolyte-coated EVs as a disposable, single-use formulation that eliminates the need for complex post-thaw processing. The polyelectrolyte coating provides sufficient cryoprotection without the toxicity issues of DMSO, allowing direct use after thawing without washing or additional steps.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the chemical parameters of the cryoprotectant from small molecules like DMSO to polyelectrolyte macromolecules. This parameter change (molecular size, charge distribution, hydrophilicity) reduces toxicity while maintaining cryoprotective effectiveness through electrostatic interactions with the EV membrane.

Inventive Principle:

Principle #35Parameter changes

2Duration of action of stationary object

If conventional cryopreservation methods are used to store EVs, then long-term storage is enabled, but structural changes and degradation occur due to ice crystal formation

Engineering Contradiction:

Improvestorage duration of EVsVSAvoidstructural integrity of EVs

Core Design Contradiction:

Duration of action of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent applies polyelectrolyte coating beforehand to the EVs before freezing. This pre-applied protective layer acts as a cushion against ice crystal formation and osmotic stress during freezing, preventing membrane rupture and structural degradation that would otherwise occur during long-term storage.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent creates a composite structure by coating EVs with polyelectrolytes. This composite material combines the biological membrane of the EV with the protective polymer layer, creating a hybrid structure that resists ice crystal damage and maintains stability during long-term frozen storage.

Inventive Principle:

Principle #40Composite materials

3Reliability

If DMSO is used as a cryoprotectant for EVs, then cryopreservation effectiveness is improved, but additional washing and re-ultracentrifugation steps are required

Engineering Contradiction:

Improvecryopreservation effectivenessVSAvoidcomplexity of post-thaw procedures

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the toxic DMSO component from the cryopreservation system and replaces it with polyelectrolytes that do not require removal. This extraction eliminates the need for washing steps and re-ultracentrifugation, simplifying the overall process while maintaining cryopreservation effectiveness.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The polyelectrolyte-coated EVs are self-sufficient after thawing, requiring no additional processing steps. The coating remains intact and functional, allowing the EVs to be used directly without external intervention for removal or purification, unlike DMSO-treated samples that require active washing and re-processing.

Inventive Principle:

Principle #25Self-service

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

Polyelectrolytes effectively stabilize EVs during cryopreservation, preserving their biological functions and structural integrity without the need for toxic compounds or complex post-thaw procedures.

Implementation Method 1

Methodology Applied

Scientific EffectCryoprotection:

Implementation Method 2

Current methods for cryopreserving extracellular vesicles (EVs) result in structural changes and degradation due to ice crystal formation and osmotic pressure changes

Methodology Applied

Scientific EffectIce crystal formation prevention:

Implementation Method 3

Methodology Applied

Scientific EffectOsmotic pressure stabilization: Osmotic Pressure

Data Source

PatentUS12495790B2Use of polyelectrolytes as cryoprotectants and a method of cryopreservation with their use

Publication Date: 2025.12.16 JAGIELLONIAN UNIVERSITY

AI summary

The subject of the invention is the use of selected polyelectrolytes from the group of synthetic and natural polyelectrolytes for the cryopreservation of human and animal extracellular vesicles. The invention also relates to a method for the cryopreservation of these vesicles, which uses said poly electrolytes.