Biodegradable Hydrogel Tissue Expanders for Reshaping

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Solution Overview

Problem

Current tissue expanders, particularly silicone-based ones, face complications such as infection, rupture, and inadequate soft tissue coverage, which can lead to graft failure due to their design requiring periodic fluid injection and external valve access, and they cannot be reshaped during surgical insertion.

Innovation Solution

Development of biodegradable, cross-linked hydrogels that are self-inflating, membrane-free, and elastic in the dry state, allowing for easy manipulation and controlled swelling, enabling them to be reshaped by surgeons before implantation and providing sufficient tissue expansion without sharp edges or rupture risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silicone-based tissue expanders are used with periodic fluid injection and external valve access, then tissue expansion function is achieved, but infection risk and device complexity increase

Engineering Contradiction:
Improvetissue expansion functionVSAvoidinfection risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes the valve and injection port components from the tissue expander system. The hydrogel expander is placed subcutaneously and expands through internal water absorption and swelling, eliminating the need for external access points that could introduce infection. This directly addresses the contradiction by extracting the harmful valve mechanism while preserving the tissue expansion function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The hydrogel tissue expander performs self-inflation through its inherent hydrophilic properties, absorbing water from surrounding tissues and swelling automatically without requiring external fluid injection. This self-service mechanism eliminates the need for periodic medical interventions and external valve access, reducing infection risk while maintaining expansion functionality.

Inventive Principle:
Principle #25Self-service

2Reliability

If silicone-based tissue expanders are used with periodic fluid injection, then tissue expansion is achieved, but device complexity and operational difficulty increase

Engineering Contradiction:
Improvetissue expansion functionVSAvoidsurgical procedure simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent eliminates the valve, injection port, and fluid reservoir components from the tissue expander design. The simplified hydrogel expander is inserted as a single unit and expands automatically through water absorption, dramatically reducing surgical complexity and eliminating the need for multiple injection procedures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The hydrogel material inherently absorbs water from surrounding tissues and swells to the desired size without requiring external fluid injection or complex operational procedures. This self-service expansion mechanism simplifies both the initial surgical implantation and subsequent expansion processes.

Inventive Principle:
Principle #25Self-service

3Reliability

If traditional tissue expanders are used, then tissue expansion function is provided, but they cannot be reshaped during surgical insertion

Engineering Contradiction:
Improvetissue expansion functionVSAvoidshape manipulation capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent utilizes the temperature-dependent physical properties of the hydrogel material. In its dry or cooled state, the hydrogel is firm and can be easily cut, shaped, and manipulated by surgical instruments. Upon contact with body temperature or moisture, it softens and swells to provide the desired tissue expansion. This parameter change allows both pre-shaping and post-implantation adaptability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The hydrogel expander transitions from a rigid, easily manipulable state during surgery to a soft, swelling state after implantation. This dynamic property change enables surgeons to shape the expander to fit specific anatomical contours during insertion, then allows the material to adapt and expand within the tissue space.

Inventive Principle:
Principle #15Dynamics

4Speed

If rapidly swelling hydrogels are used, then quick tissue expansion is achieved, but tissue trauma and rupture risk increase

Engineering Contradiction:
Improveexpansion speedVSAvoidtissue trauma
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The hydrogel expander absorbs water and swells gradually over time through a controlled, periodic process rather than rapid instantaneous expansion. This gradual swelling allows surrounding tissues to adapt and accommodate the expanding volume, reducing the risk of tissue trauma, necrosis, or rupture while still achieving the desired expansion effect.

Inventive Principle:
Principle #19Periodic action

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 hydrogels offer a biocompatible, minimally invasive solution with controlled tissue expansion, reducing complications like infection and tissue trauma, and allowing for precise shaping and placement, enhancing surgical outcomes by providing adequate soft tissue coverage for bone grafts.

Implementation Method 1

Hydrogels are biocompatible, self-inflating and membrane-free. They swell slowly

Methodology Applied
Scientific EffectOsmosis: Osmosis

Implementation Method 2

novel, biodegradable, cross-linked hydrogels that are useful as tissue expanders

Methodology Applied
Scientific EffectHydrogel: Hydrogel

Implementation Method 3

These hydrogels are biocompatible, self-inflating and membrane-free. They swell slowly and elicit minimal tissue response, while allowing for easy manipulation by a medical practitioner at the time of emplacement

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3131953B1Novel hydrogel tissue expanders
Publication Date: 2019.08.07 AKINA INC
  • EP3131953B1 patent drawingFigure 1
  • EP3131953B1 patent drawingFigure 2
  • EP3131953B1 patent drawingFigure 3

AI summary

The present invention provides tissue expanders comprising biodegradable, chemically cross-linked hydrogels which are elastic in the dry state. These biocompatible tissue expanders are self-inflating and membrane-free. They swell slowly and elicit minimal negative tissue responses, while allowing for rapid and easy manipulation by the surgeon at the time of emplacement.