Isogenic iPSC Blood-Brain Barrier Model

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Solution Overview

Problem

Current in vitro Blood-Brain Barrier (BBB) models lack representativeness due to de-differentiation of primary and transformed brain microvascular endothelial cells (BMECs) when removed from the brain microenvironment, and the limitations of using primary cells from various animal sources for human disease modeling.

Innovation Solution

Development of an isogenic BBB model using induced pluripotent stem cells (iPSCs) differentiated into BMECs, astrocytes, and neurons from the same human source, co-cultured to induce BBB properties and enhance barrier tightening, tight junction continuity, and efflux transporter activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If primary and transformed BMECs are removed from the brain microenvironment for in vitro modeling, then the BBB model becomes accessible and scalable, but the cells de-differentiate and lose barrier properties

Engineering Contradiction:

ImproveAccessibility of BBB modelVSAvoidBarrier properties of BMECs

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the developmental stage parameter by using embryonic BMECs (which have not yet de-differentiated) instead of adult primary BMECs. This parameter change allows the cells to maintain their barrier properties longer in culture while still being accessible for in vitro modeling. The embryonic origin provides a more primitive, undifferentiated state that resists de-differentiation better than adult cells.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary approach by using immortalized BMEC lines that have been engineered to maintain barrier properties through specific genetic modifications or cultural conditions. These intermediary cell lines serve as a bridge between primary cells (which have good barrier properties but poor scalability) and transformed cells (which are scalable but have lost barrier properties).

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If freshly isolated human BMECs are used to model the BBB, then human-specific BBB properties can be studied, but the cells exhibit sub-par BBB phenotypes due to de-differentiation

Engineering Contradiction:

ImproveHuman BBB phenotype accuracyVSAvoidBBB barrier function

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent changes the source parameter from adult human BMECs to embryonic human BMECs. This parameter change provides human-specific genetic background for studying human BBB properties while the embryonic origin ensures better maintenance of barrier phenotypes. The embryonic cells have not undergone the de-differentiation process that occurs in adult cells, thus maintaining tighter junctions and better barrier function.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If multicellular BBB models including NVU cells are created, then the representativeness of BBB function is improved, but the model complexity increases

Engineering Contradiction:

ImproveRepresentativeness of BBB functionVSAvoidMulticellular model structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple cell types (embryonic BMECs, astrocytes, pericytes, and neurons) into a co-culture system that recreates the neurovascular unit architecture. This merging allows the model to represent the complex interactions occurring in the native BBB while maintaining experimental tractability through a unified culture system.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the BBB model into distinct functional components (endothelial cells forming the barrier, astrocytes providing structural support, pericytes regulating blood flow, and neurons representing the brain parenchyma). This segmentation allows each cell type to be optimized independently while maintaining their native interactions, improving representativeness without excessive complexity.

Inventive Principle:

Principle #1Segmentation

4Productivity

If stem cell based models are used to differentiate human BMEC-like cells, then the model becomes scalable and renewable, but the cells may not fully recapitulate native BMEC properties

Engineering Contradiction:

ImproveScalability of BBB modelVSAvoidBMEC phenotype accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent changes the differentiation target parameter by directing stem cells to differentiate into embryonic BMECs rather than adult BMECs. This parameter change allows scalable production of cells that maintain primitive, undifferentiated characteristics and better barrier properties. The embryonic BMEC phenotype is more resistant to de-differentiation and maintains tighter junctions throughout culture.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11840708B2Isogenic blood-brain barrier model

Publication Date: 2023.12.12 WISCONSIN ALUMNI RES FOUND

AI summary

A method of creating an isogenic multicellular blood-brain barrier model from iPSCs is disclosed.