Serum-Free Colorectal Stem Cell Culture Medium

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Solution Overview

Problem

Current methods for culturing colorectal epithelial stem cells in vitro are inefficient and unable to maintain stemness, and there is no established protocol for using these cells for repairing damaged tissues in human bowel diseases.

Innovation Solution

A culture medium comprising serum albumin, Wnt3a, and r-spondin-1, with optional EGF, HGF, and Noggin, allows for the long-term maintenance and propagation of colorectal epithelial stem cells in a serum-free environment, which can be administered to damaged colons to enhance recovery from acute colitis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional culture media with serum and multiple growth factors are used, then cell proliferation may be supported, but stemness maintenance fails and culture efficiency is low

Engineering Contradiction:
Improvestemness maintenanceVSAvoidculture efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention changes the chemical composition parameters of the culture medium by replacing serum-based components with a defined serum-free formulation containing specific concentrations of Wnt3a (50-500 ng/mL), r-spondin1 (10-100 ng/mL), and EGF (10-50 ng/mL). This parameter optimization enables both stemness maintenance and high culture efficiency simultaneously

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite culture medium system that integrates multiple signaling pathway activators (Wnt, R-spondin, EGF) with a basal medium (DMEM/F12) and extracellular matrix components. This composite formulation synergistically supports both stem cell proliferation and stemness maintenance

Inventive Principle:
Principle #40Composite materials

2Reliability

If complex culture conditions with multiple components are used, then cell survival may be improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvecell survivalVSAvoidculture medium complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates complex serum components and unnecessary growth factors from conventional culture media, retaining only the essential three components (Wnt3a, r-spondin1, EGF) that are critical for colorectal epithelial stem cell survival. This simplification reduces manufacturing complexity while maintaining cell survival

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention defines specific concentration ranges for each component (Wnt3a: 50-500 ng/mL, r-spondin1: 10-100 ng/mL, EGF: 10-50 ng/mL) to optimize cell survival within a simplified formulation, reducing the need for complex medium compositions

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If large amounts of tissue are required for culture, then sufficient cell numbers may be obtained, but clinical application becomes difficult

Engineering Contradiction:
Improvecell numberVSAvoidtissue requirement
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The invention enables preliminary expansion of colorectal epithelial stem cells in vitro using the optimized culture medium before transplantation. This preliminary culture step allows small biopsy samples (minimal tissue requirement) to generate sufficient cell numbers for clinical therapy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The enhanced proliferation capability achieved through optimized growth factor concentrations enables rapid cell expansion from minimal starting tissue, generating sufficient cell numbers for clinical applications without requiring large biopsy samples

Inventive Principle:
Principle #35Parameter changes

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 described method enables the stable and reproducible culture of colorectal epithelial stem cells, allowing them to engraft and form functional, self-renewable colonic crypts, effectively preventing and treating bowel diseases with reduced costs and minimal tissue requirements.

Implementation Method 1

Wnt3a is a protein encoded by a WNT3A gene and is known to activate the β-catenin pathway. The Wnt/β-catenin pathway is known to be involved in proliferation of stem cells and maintenance of undifferentiation.

Methodology Applied
Scientific EffectWnt/β-catenin signaling pathway:

Implementation Method 2

R-spondin-1 (Roof-plate-specific Spondin-1: Rspo1) is a protein encoded by an RSPO1 gene and is known to contribute to differentiation of the dorsal neural tube and to enhance the proliferation of intestinal crypt epithelial cells.

Methodology Applied
Scientific EffectR-spondin-1 signaling:

Implementation Method 3

An epidermal growth factor (EGF) is a protein encoded by an EGF gene and is known to enhance the proliferation of epithelial cells.

Methodology Applied
Scientific EffectEpidermal growth factor signaling:

Implementation Method 4

A hepatocyte growth factor (HGF) is a protein encoded by an HGF gene and is known to enhance the proliferation of various cells including hepatocytes.

Methodology Applied
Scientific EffectHepatocyte growth factor signaling:

Implementation Method 5

Noggin is a protein encoded by an NOG gene and is known to inhibit the signaling of transforming growth factor beta (TGF-β).

Methodology Applied
Scientific EffectNoggin inhibition:

Data Source

PatentEP2772534B1Culturing colorectal epithelial stem cells and transplanting colorectal epithelium
Publication Date: 2019.09.18 NAT UNIV CORP TOKYO MEDICAL & DENTAL UNIV
  • EP2772534B1 patent drawingFigure 1a~2b
  • EP2772534B1 patent drawingFigure 3a~3d
  • EP2772534B1 patent drawingFigure 4a~4f

AI summary

It is an object of the present invention to provide a culture medium for in vitro culture of a colorectal epithelial stem cell or the like, a method of in vitro culturing a colorectal epithelial stem cell or the like using the culture medium, a prophylactic or therapeutic agent for a bowel disease containing a colorectal epithelial stem cell or the like cultured by the method, a method of administrating, i.e., transplanting a colorectal epithelial stem cell or the like cultured by the method to a bowel disease patient, and a method of isolating a colorectal epithelial stem cell or the like. The culture medium for in vitro culture of a colorectal epithelial stem cell and/or a colorectal epithelial cell characteristically contains serum albumin, Wnt3a, and r-spondin-1.