Endogenous Bioengineered Skin Model via Dynamic Fibroblast Seeding

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Solution Overview

Problem

Current human skin equivalent models are not similar enough to native skin, containing a considerable exogenous portion, which limits their reliability for studies, especially those requiring an endogenous extracellular matrix, such as assessing UV radiation effects on collagen and elastin function.

Innovation Solution

A method to produce a totally endogenous bioengineered skin model with a dermis and epidermis layer using dynamic seeding of fibroblasts on biodegradable porous microbeads, followed by maturation in a specialized chamber, resulting in a skin equivalent with a fully organized endogenous extracellular matrix, mimicking native skin.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If non-human biopolymers (exogenous scaffold) are used to form dermis equivalent, then successful HSE formation is achieved, but the model contains considerable exogenous portion and cannot reproduce native ECM organization

Engineering Contradiction:
ImproveHSE formation successVSAvoidArtificial character of model
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies self-service by enabling fibroblasts to autonomously produce their own extracellular matrix components (collagen, elastin, proteoglycans) without requiring exogenous scaffolds. The fibroblasts are cultured in a defined medium that triggers endogenous ECM synthesis, allowing the tissue to build itself from within rather than relying on externally provided structural support.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts and removes the exogenous scaffold component from the HSE model. By eliminating non-human biopolymers and replacing them with fibroblast-derived endogenous ECM, the model achieves a purely human-origin dermis equivalent that closely mimics native skin architecture and composition.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If fibroblast sheets are used as dermal equivalent to provide endogenous ECM, then native ECM is present, but cell content is higher than native dermis and only very small thickness can be obtained

Engineering Contradiction:
ImproveNative ECM presenceVSAvoidDermis thickness
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The patent applies local quality by creating a three-dimensional distributed network of fibroblasts embedded within self-produced ECM, rather than using dense fibroblast sheets. This spatial distribution allows different regions to have appropriate cell densities and ECM compositions, enabling the formation of thick dermis equivalents with physiological architecture that mimics native skin.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transitions from two-dimensional fibroblast sheets to three-dimensional fibroblast-ECM constructs. By culturing fibroblasts in suspension or on porous supports that enable 3D ECM deposition, the model achieves substantial dermis thickness while maintaining physiological cell-to-ECM ratios and native-like organization.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If exogenous scaffold is used to support fibroblasts, then HSE formation is enabled, but the ECM is not fully endogenous and artificial character increases

Engineering Contradiction:
ImproveHSE formation capabilityVSAvoidEndogeneity of ECM
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-conditioning fibroblasts in a defined culture medium that stimulates endogenous ECM synthesis before implantation or further culture. This preparatory step ensures that fibroblasts are primed to produce sufficient collagen, elastin, and other ECM components, eliminating the need for exogenous scaffolds while maintaining HSE formation capability.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3137594B1Method for producing a totally endogenous bioengineered tissue and tissue obtained thereby
Publication Date: 2018.03.28 FOND INST ITAL DI TECH
  • EP3137594B1 patent drawingFigure 1~2
  • EP3137594B1 patent drawingFigure 3~5
  • EP3137594B1 patent drawingFigure 6~7

AI summary

The present invention relates to a method for producing a totally endogenous bioengineered tissue including a first layer of connective tissue and a second layer of epithelial tissue, to a tissue equivalent obtained thereby and to a method for determining the effect of a chemical substance or an agent on skin employing the tissue equivalent.