Dry Collagen Fiber Tissue Preservation via Gradient Dehydration

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Solution Overview

Problem

Current methods for preserving animal-derived collagen fiber tissues for bioprostheses, such as those using aldehyde solutions or lyophilization, face issues like toxicity, morphological deformation, high costs, and difficulties in rehydration, necessitating improved methods for maintaining tissue flexibility and controlling water content for effective sterilization.

Innovation Solution

A method involving rinsing crosslinked collagen fiber tissues with an isotonic solution, followed by dehydration in a non-aqueous alcoholic solution and subsequent gradient saccharide solutions, then drying and hermetic packaging for sterilization, which results in a flexible, residue-free, and controllably hydrated dry tissue material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If glutaraldehyde is used for preservation, then tissue sterility and structural stability are improved, but tissue toxicity and calcification risk increase

Engineering Contradiction:
Improvetissue sterilityVSAvoidtissue toxicity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes glutaraldehyde from the preservation system entirely, replacing it with a non-toxic preservation method that uses controlled dehydration and sterilization processes to achieve the same protective functions without harmful residues

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a single-use preservation protocol where tissues are preserved in a controlled manner and then sterilized, eliminating the need for long-term toxic preservative exposure and multiple rinsing cycles required by glutaraldehyde methods

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Duration of action of stationary object

If lyophilization is used for drying, then tissue preservation is improved, but tissue toughness and rehydration speed deteriorate

Engineering Contradiction:
Improvetissue preservationVSAvoidtissue toughness
Core Design Contradiction:
Duration of action of stationary objectVSStrength

Solution Approach 1:

The patent changes the drying parameters by controlling water content to a specific range (10-25%) rather than complete drying, and uses non-aqueous solvents to replace water gradually, preventing the formation of brittle structures while maintaining preservation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary dehydration using non-aqueous solvents before final drying, which prevents ice crystal formation and structural damage that would occur with direct freeze-drying, thereby maintaining tissue toughness

Inventive Principle:
Principle #10Preliminary action

3Reliability

If complete drying is applied, then sterilization effectiveness is improved, but tissue flexibility and rehydration difficulty worsen

Engineering Contradiction:
Improvesterilization effectivenessVSAvoidtissue flexibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent optimizes the water content parameter to a specific range (10-25%) that balances sterilization effectiveness with tissue flexibility, avoiding complete drying while ensuring sufficient moisture removal for safe sterilization

Inventive Principle:
Principle #35Parameter changes

4Object-affected harmful factors

If multiple rinsing cycles are used to remove glutaraldehyde, then tissue toxicity is reduced, but production time and complexity increase

Engineering Contradiction:
Improvetissue toxicityVSAvoidproduction time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The patent eliminates glutaraldehyde from the process entirely, removing the need for multiple rinsing cycles and significantly reducing production time and complexity while maintaining tissue safety

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a streamlined preservation and sterilization protocol that requires minimal processing steps, reducing both time and operational complexity compared to traditional glutaraldehyde methods

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 method produces biocompatible, flexible, and mechanically robust dry collagen fiber tissues that can be rehydrated quickly, with reduced toxicity and calcification potential, suitable for mass production and safe clinical use, while maintaining the original tissue structure and properties.

Implementation Method 1

immersing the rinsed biological tissue in a non-aqueous alcoholic solution for dehydration

Methodology Applied
Scientific EffectDehydration:

Implementation Method 2

successively immersing the biological tissue that has been dehydrated with the non-aqueous alcoholic solution in saccharide solutions of increasing concentrations for gradient dehydration

Methodology Applied
Scientific EffectOsmosis: Osmosis

Implementation Method 3

taking out and drying of the gradient dehydrated tissue material

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3296391B1Dry animal-derived collagen fiber tissue material and preparation method and bioprosthesis thereof
Publication Date: 2021.10.06 SHANGHAI MICROPORT CARDIOFLOW MEDTECH CO LTD
  • EP3296391B1 patent drawingFigure 1~2
  • EP3296391B1 patent drawingFigure 3~4

AI summary

A dry animal-derived collagen fiber tissue material and preparation method and bioprosthesis thereof are disclosed. The preparation method includes: 1) rinsing of an animal-derived collagen fiber tissue material that has been treated with a crosslinking agent; 2) immersion of the rinsed tissue material in a non-aqueous alcoholic solution for dehydration; 3) successive immersion of the tissue material that has been dehydrated with the non-aqueous alcoholic solution in saccharide solutions of different gradients of concentrations for gradient dehydration; 4) taking out and drying of the gradient dehydrated tissue material; and 5) hermetic packaging of the dried tissue material and sterilization. The preparation method is simple and allows the use of easily-available low-cost materials, resulting in lower costs. In addition, it can reduce the toxicity caused by a residue of the aldehyde crosslinking agent. The prepared biological tissue material is pliable and tough, less prone to bending or warping, has a water content that can be well controlled and better biocompatibility due to absence of polyhydric alcohol residues.