Bioabsorbable Self-Cohered Web Materials for Implantable Devices

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Solution Overview

Problem

Existing bioabsorbable polymeric web materials lack high porosity, mechanical strength, loft, suppleness, drapability, and tissue compliance, limiting their effectiveness in medical applications such as wound closure and reconstruction.

Innovation Solution

A synthetic bioabsorbable, non-woven, self-cohered polymeric web material with high porosity is developed by stretching unannealed precursor web materials in one or more directions followed by heat-setting, resulting in filaments with increased void space and birefringence, enhancing mechanical strength and tissue compatibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional bioabsorbable polymeric web materials are used, then they can be produced with basic structural integrity, but they lack high porosity, mechanical strength, loft, suppleness, drapability, and tissue compliance

Engineering Contradiction:
Improvemechanical strengthVSAvoidporosity
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The patent applies porous materials by creating a highly porous non-woven web structure through a two-stage process: first forming a self-cohered web from stretched filaments, then applying a porous forming agent (such as expandable beads or foam) that creates additional porosity when activated. This results in a material with interconnected pores ranging from microporous to macroporous structures, achieving high porosity (50-90%) while maintaining mechanical strength through the self-cohered filament network that provides structural integrity.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent employs composite materials by combining multiple polymeric components with different functions: a first polymeric component forms the self-cohered filament network providing mechanical strength, while a second polymeric component (porous forming agent) creates the porous structure. These components are integrated into a single non-woven web material that exhibits both structural integrity and high porosity, resolving the contradiction between strength and porosity.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If the web material is made more porous to improve tissue compliance and loft, then mechanical strength may be compromised

Engineering Contradiction:
Improvetissue complianceVSAvoidmechanical strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent applies local quality by creating different pore sizes and distributions within the web material - microporous regions provide tissue compliance and cellular interaction, while the self-cohered filament network provides structural strength. The material has heterogeneous properties at different locations and scales, with the filament framework providing strength locally while the porous spaces provide compliance locally, resolving the contradiction between tissue compliance and mechanical strength.

Inventive Principle:
Principle #3Local quality

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 resulting web material exhibits increased mechanical strength, loft, suppleness, and tissue compliance, making it suitable for implantable medical devices and thrombogenic agents, while maintaining bioabsorbability for physiological removal.

Implementation Method 1

stretching unannealed precursor web materials in one or more directions followed by heat-setting, resulting in filaments with increased void space and birefringence

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

stretching unannealed precursor web materials in one or more directions followed by heat-setting

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 3

The continuous filaments are produced by selecting spinning conditions that provide a tackiness to the emerging filaments and allows them to self-cohere as solid filaments as the filaments are collected in a cohesive random pile, or web, on a collecting surface. The self-cohered filaments have multiple contact points with each other within the web. The self-cohered filaments bond at the contact points without need for requisite addition of supplementary adhesives, binders, adhesive adjuncts

Methodology Applied
Scientific EffectCovalent bonding: Chemical Bonding

Implementation Method 4

These processes can include simple dissolution of all or part of the bioabsorbable compound, hydrolysis of labile chemical bonds in the bioabsorbable compound, enzymatic action, and/or surface erosion of the material

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 5

These processes can include simple dissolution of all or part of the bioabsorbable compound, hydrolysis of labile chemical bonds in the bioabsorbable compound, enzymatic action, and/or surface erosion of the material

Methodology Applied
Scientific EffectEnzymatic action: Enzyme

Data Source

PatentEP1909696B1Composite self-cohered web materials
Publication Date: 2014.12.24 WL GORE & ASSOC INC
  • EP1909696B1 patent drawingFigure 1
  • EP1909696B1 patent drawingFigure 1A
  • EP1909696B1 patent drawingFigure 2~2A

AI summary

The present invention is directed to implantable bioabsorbable non-woven self-cohered web materials having a high degree of porosity. The web materials are very supple and soft, while exhibiting proportionally increased mechanical strength in one or more directions. The web materials often possess a high degree of loft. The web materials can be formed into a variety of shapes and forms suitable for use as implantable medical devices or components thereof.