Biocompatible Membrane Composite for Immune Isolation and Vascularization

Solution Overview

Problem

Existing implantable devices face challenges in maintaining the viability of encapsulated bioactive entities due to the formation of foreign body giant cells, which hinder the formation of blood vessels near the cell impermeable interface, restricting access to oxygen and nutrients.

Innovation Solution

A biocompatible membrane composite with a first layer having a maximum pore size less than 1 micron and a second layer with bonded solid features spaced less than 50 microns, intimately bonded to the first layer, providing immune isolation while promoting vascularization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cell impermeable membrane is used to encapsulate cells, then immune isolation is provided, but foreign body giant cells form and prevent blood vessel formation near the interface

Engineering Contradiction:

Improveimmune isolationVSAvoidforeign body giant cell formation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The membrane is divided into two distinct layers: a first layer providing immune isolation with small pores, and a second layer promoting vascularization with larger pores and solid features. This segmentation allows each layer to perform its specific function without interfering with the other, resolving the contradiction between immune isolation and vascularization.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the membrane have different properties: the first layer has small pores for immune isolation, while the second layer has larger pores and bonded solid features spaced less than 50 microns to promote blood vessel formation. This local differentiation allows the membrane to simultaneously provide immune isolation and facilitate vascularization at different locations.

Inventive Principle:

Principle #3Local quality

2Reliability

If blood vessels are prevented from forming near the cell impermeable interface, then immune isolation is maintained, but access to oxygen and nutrients is restricted

Engineering Contradiction:

Improveimmune isolationVSAvoidoxygen and nutrient access

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The membrane is divided into two distinct layers: a first layer providing immune isolation with small pores, and a second layer promoting vascularization with larger pores and solid features. This segmentation allows each layer to perform its specific function without interfering with the other, resolving the contradiction between immune isolation and vascularization.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second layer acts as an intermediary between the immune-isolating first layer and the host tissue, facilitating blood vessel formation and nutrient transport while the first layer maintains immune isolation. This intermediary layer resolves the contradiction by mediating between isolation and nourishment requirements.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If a porous structure is used to promote vascularization, then blood vessel formation is enhanced, but immune isolation capability is reduced

Engineering Contradiction:

Improvevascularization promotionVSAvoidimmune isolation

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The membrane is divided into two distinct layers: a first layer providing immune isolation with small pores, and a second layer promoting vascularization with larger pores and solid features. This segmentation allows each layer to perform its specific function without interfering with the other, resolving the contradiction between immune isolation and vascularization.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the membrane have different properties: the first layer has small pores for immune isolation, while the second layer has larger pores and bonded solid features spaced less than 50 microns to promote blood vessel formation. This local differentiation allows the membrane to simultaneously provide immune isolation and facilitate vascularization at different locations.

Inventive Principle:

Principle #3Local quality

4Quantity of substance

If the membrane is made thinner to reduce diffusion distance, then nutrient access is improved, but mechanical strength is reduced

Engineering Contradiction:

Improvenutrient diffusion efficiencyVSAvoidmembrane mechanical strength

Core Design Contradiction:

Quantity of substanceVSStrength

Solution Approach 1:

The membrane uses a composite structure with two layers made of different materials with distinct properties. The first layer provides immune isolation, while the second layer promotes vascularization and provides mechanical support through bonded solid features. This composite structure allows optimization of both diffusion efficiency and mechanical strength.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The membrane is divided into two distinct layers: a first layer providing immune isolation with small pores, and a second layer promoting vascularization with larger pores and solid features. This segmentation allows each layer to perform its specific function without interfering with the other, resolving the contradiction between immune isolation and vascularization.

Inventive Principle:

Principle #1Segmentation

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 membrane composite effectively mitigates the foreign body response, allowing sufficient blood vessel formation near the encapsulated cells, ensuring access to oxygen and nutrients, thereby maintaining cell viability and functionality.

Implementation Method 1

the first layer has an MPS (maximum pore size) less than about 1 micron... permit the passage of nutrients through but prevent the passage of the cells encapsulated therethrough

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

a second layer having a majority of bonded solid features having a solid feature spacing less than about 50 microns... providing immune isolation while promoting vascularization

Methodology Applied

Scientific EffectVascularization:

Data Source

PatentUS20250325360A1Biocompatible membrane composite

Publication Date: 2025.10.23 WL GORE & ASSOC INC

AI summary

A biocompatible membrane composite including a cell impermeable layer and a mitigation layer is provided. The cell impermeable layer is impervious to vascular ingrowth and prevents cellular contact from the host. Additionally, the mitigation layer includes solid features. In at least one embodiment, mitigation layer has therein bonded solid features. In some embodiments, the cell impermeable layer and the mitigation layer are intimately bonded or otherwise connected to each other to form a composite layer having a tight/open structure. A reinforcing component may optionally be positioned external to or within the biocompatible membrane composite to provide support to and prevent distortion. The biocompatible membrane composite may be used in or to form a device for encapsulating biological entities, including, but not limited to, pancreatic lineage type cells such as pancreatic progenitors.