Porous Elastomer Coating for Implantable Devices

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Solution Overview

Problem

Implantable medical devices often induce a foreign body response leading to fibrous capsule formation and capsular contracture, which can cause aesthetic and painful issues, and existing textured surfaces do not adequately prevent these complications.

Innovation Solution

A porous material with a substantially non-degradable, biocompatible elastomer matrix featuring an array of interconnected pores is created through a method involving fusing porogens, coating with an elastomer, curing, and removing the porogen scaffold, which promotes cellular ingrowth and reduces fibrous capsule formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a smooth surface is used for implantable medical devices, then manufacturing is simple, but fibrous capsule formation and capsular contracture occur

Engineering Contradiction:
Improvesurface fabrication simplicityVSAvoidfibrous capsule formation
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies porous materials by creating a porous coating layer on the implantable device surface. This porous structure allows cellular ingrowth into the material, promoting tissue integration and preventing fibrous capsule formation. The pores are formed through a phase separation process where a porogen is mixed with polymer, cured, and then the porogen is extracted, leaving a controlled porous architecture that facilitates biological integration while maintaining manufacturing feasibility.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent uses composite materials by combining polymer matrices with porogen phases to create a composite coating structure. The composite consists of a polymer network (e.g., polyurethane, polyester, or silicone-based polymers) integrated with a porogen phase that, when removed, creates the porous architecture. This composite approach enables control over pore size, distribution, and connectivity while maintaining the mechanical properties needed for implantable devices.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If a textured surface is imprinted onto the implant, then capsular formation is reduced, but the surface architecture is limited to hills and valleys

Engineering Contradiction:
Improvecapsular formation reductionVSAvoidsurface architecture complexity
Core Design Contradiction:
Object-affected harmful factorsVSShape

Solution Approach 1:

The patent transitions from surface-level texturing to volumetric porosity by creating a porous coating layer with interconnected pores extending through the coating thickness. This three-dimensional porous architecture allows cellular ingrowth throughout the coating volume, not just at the surface, providing enhanced tissue integration and more effective prevention of capsular formation compared to traditional surface texturing.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent adds a third dimension to surface architecture by creating pores that extend through the coating thickness rather than仅限于 surface features. This dimensional transition from 2D surface texturing to 3D volumetric porosity enables cellular ingrowth into the material bulk, providing more effective tissue integration and preventing capsular contracture through enhanced biological interaction.

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

3Shape

If porous material is created through phase separation and porogen extraction, then interconnected pore network is formed, but manufacturing process complexity increases

Engineering Contradiction:
Improvepore network connectivityVSAvoidmanufacturing process steps
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-forming the porous structure within the coating material before implantation. The porogen is mixed with the polymer and cured to create the porous architecture in advance, and then the porogen is extracted to leave the desired pore network. This preliminary formation of the porous structure eliminates the need for complex post-implantation processing or sophisticated real-time manufacturing techniques.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses an intermediary substance (porogen) to create the porous structure. The porogen acts as a temporary phase that is mixed with the polymer, cured, and then extracted to leave the desired pore network. This intermediary approach simplifies the manufacturing process compared to direct pore formation methods, as the porogen provides a straightforward mechanism for creating interconnected pores through phase separation and extraction.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 porous material effectively reduces or prevents fibrous capsule formation and capsular contracture, enhancing the integration of implantable devices while maintaining mechanical strength and preventing scarring.

Implementation Method 1

coating the porogen scaffold with an elastomer base to form an elastomer coated porogen scaffold

Methodology Applied
Scientific EffectCoating: Coatings

Implementation Method 2

curing the elastomer coated porogen scaffold

Methodology Applied
Scientific EffectCuring:

Implementation Method 3

removing the porogen scaffold, wherein porogen scaffold removal results in a porous material

Methodology Applied
Scientific EffectExtraction:

Data Source

PatentEP2569473B1Porous materials, methods of making and uses
Publication Date: 2019.10.16 ALLERGAN INC
  • EP2569473B1 patent drawingFigure 1A
  • EP2569473B1 patent drawingFigure 1B
  • EP2569473B1 patent drawingFigure 2A~2D

AI summary

The present specification discloses porous materials, methods of forming such porous materials, biocompatible implantable devices comprising such porous materials, and methods of making such biocompatible implantable devices.