Stem Cell Tooth-Like Structure Regeneration via Epithelial Differentiation

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Solution Overview

Problem

Current methods using induced pluripotent stem cells (iPSCs) have not successfully generated solid organs or tissues such as teeth, limiting their application in regenerative medicine.

Innovation Solution

A method involving the use of stem cells, specifically induced pluripotent stem cells or embryonic stem cells, to form epithelial-like cells, which are then recombined with dental mesenchyme and transplanted to form tooth-like structures through xenograft transplantation, using a culture medium comprising DMEM/F12, N2 supplement, retinoic acid, and BMP-4 to induce differentiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If induced pluripotent stem cells are used for differentiation, then cell source versatility is improved, but solid organ or tissue generation capability remains insufficient

Engineering Contradiction:
Improvecell source versatilityVSAvoidsolid organ generation capability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The tooth is segmented into distinct tissue components (enamel, dentin, pulp, cementum) that are generated through sequential differentiation stages. The method divides the complex organogenesis process into manageable phases: epithelial cell formation, dental mesenchyme induction, and tissue-specific differentiation, allowing each component to be optimized independently while contributing to the whole tooth structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by first generating epithelial-like cells from iPSCs before combining them with dental mesenchyme. This sequential approach prepares the cellular components in advance with specific characteristics (epithelial markers, morphology) that are necessary for subsequent tooth formation, ensuring that each cell type is ready for its designated role in the organogenesis process.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If complex differentiation protocols are used, then cell differentiation capability is improved, but process complexity increases

Engineering Contradiction:
Improvecell differentiation capabilityVSAvoiddifferentiation protocol complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent utilizes parameter changes by systematically varying culture conditions including growth factor concentrations (BMP-4, FGF-2, Wnt3a), medium composition, and oxygen tension to guide stem cell differentiation through specific developmental stages. These controlled parameter adjustments enable precise temporal and spatial regulation of gene expression and cell fate decisions without requiring overly complex procedural interventions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces intermediary substances such as growth factors and signaling molecules that mediate the differentiation process. These intermediaries (BMP-4, FGF-2, Wnt3a) act as chemical messengers that translate complex differentiation instructions into cellular responses, simplifying the overall protocol by using naturally occurring mediators rather than direct mechanical or genetic manipulation at each step.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If xenograft transplantation is used, then tooth-like structure formation is improved, but immunological compatibility challenges arise

Engineering Contradiction:
Improvetooth-like structure formationVSAvoidimmunological rejection
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent creates tooth-like structures that copy the essential organizational principles and tissue architecture of natural teeth without requiring complete genetic identity with the host. The regenerated structures replicate key functional features (enamel organ, dental papilla, Hertwig's epithelial root sheath) that can be recognized and integrated by the host immune system, reducing rejection while maintaining structural fidelity.

Inventive Principle:
Principle #26Copying

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 effectively produces tooth-like structures with characteristics similar to adult human teeth, including dental pulp, dentin, enamel space, and enamel organ, with the hardness of enamel in regenerative teeth reaching one-eighth of that in adult human teeth, demonstrating successful tooth regeneration.

Implementation Method 1

a culture medium may comprise: a basal medium, which is DMEM/F12 medium; a N2 supplement; a retinoic acid; and a BMP-4. The inventors surprisingly find that the above cited culture medium may be effectively used to induce the differentiation of stem cell into epithelial-like cell.

Methodology Applied
Scientific EffectDifferentiation induction by culture medium components:

Implementation Method 2

a retinoic acid; and a BMP-4. The inventors surprisingly find that the above cited culture medium may be effectively used to induce the differentiation of stem cell into epithelial-like cell.

Methodology Applied
Scientific EffectSignal transduction:

Implementation Method 3

the epithelial-like cell is recombined with a dental mesenchyme of another animal and cultured to form a reconstituted explant prior to the xenograft transplantation

Methodology Applied
Scientific EffectSelf-assembly: Self-Assembly

Implementation Method 4

the tooth-like structure contains ameloblast. The immunohistochemistry staining with Ameloblastin (Amel, 1:100, Santa, Cat. NO. sc-50534) may be used to describe the appearance of enamel-secreting ameloblasts in the tooth-like structures

Methodology Applied
Scientific EffectMorphogenesis:

Implementation Method 5

The immunohistochemistry staining with Ameloblastin (Amel, 1:100, Santa, Cat. NO. sc-50534) may be used to describe the appearance of enamel-secreting ameloblasts in the tooth-like structures

Methodology Applied
Scientific EffectBiomineralization:

Data Source

PatentEP2954047B1Preparing tooth-like structure using stem cell
Publication Date: 2019.08.28 GUANGZHOU INSTITUTES OF BIOMEDICINE AND HEALTH CHINESE ACADEMY OF SCIENCES
  • EP2954047B1 patent drawingFigure 1
  • EP2954047B1 patent drawingFigure 2a~2e
  • EP2954047B1 patent drawingFigure 3a~3f

AI summary

The usage of a stem cell in preparation of a tooth-like structure is provided. And a culture medium, a method for preparing an epithelial-like cell, a kit for preparing an ameloblast, a method for preparing an ameloblast are also provided. Specifically, the culture medium comprises a basal medium, which is DMEM/F12 medium; N2 supplement; retinoic acid; and BMP -4.