Swellable Polyether-Ester Yarns for Biomedical Sutures

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Solution Overview

Problem

Existing biomedical devices, such as surgical sutures and tissue engineering scaffolds, require polyether-esters with higher molecular weight and degree of crystallinity to achieve high strength and compliance in aqueous environments, which existing technologies fail to meet effectively.

Innovation Solution

Development of high molecular weight, crystalline polyether-esters with a polyether chain component exceeding 11 kDa, inherent viscosity of at least 0.8 dL/g, and heat of fusion exceeding 5 J/g, capable of swelling by 0.5% in an aqueous environment within three hours, and incorporating bioactive agents for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If polyether glycol intermediates with low molecular weight (≤10 kDa) are used, then the polyether-esters can be produced more easily, but the resulting fibers lack sufficient strength and crystallinity for biomedical applications

Engineering Contradiction:
Improveease of productionVSAvoidfiber strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies parameter changes by specifying a minimum molecular weight of 11 kDa for polyether glycol intermediates, thereby changing the molecular weight parameter from the conventional ≤10 kDa range to ≥11 kDa. This parameter change enables the production of high strength, crystalline polyether-esters suitable for biomedical applications while maintaining ease of manufacture through established polymerization processes.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If polyether glycol intermediates with low molecular weight (≤10 kDa) are used, then the production process is simpler, but the degree of crystallinity remains insufficient for high strength yarn production

Engineering Contradiction:
Improveproduction simplicityVSAvoiddegree of crystallinity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent changes the molecular weight parameter of polyether glycol intermediates to ≥11 kDa, which directly influences the degree of crystallinity of the resulting polyether-esters. This parameter change enables the formation of sufficiently crystalline structures (as evidenced by heat of fusion exceeding 5 J/g) while maintaining production simplicity through standardized polymerization procedures.

Inventive Principle:
Principle #35Parameter changes

3Strength

If high molecular weight polyether glycol intermediates (≥11 kDa) are used, then high strength and crystallinity are achieved, but the amphiphilicity may be reduced affecting swellability

Engineering Contradiction:
Improveyarn strengthVSAvoidamphiphilicity
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by creating an amphiphilic block copolymer structure where hydrophobic polyester blocks (providing strength and crystallinity) and hydrophilic polyether blocks (providing swellability) are segregated into distinct segments. This local differentiation of properties within the polymer chain enables simultaneous achievement of high strength through crystalline polyester regions and adequate swellability through hydrophilic polyether regions, even with high molecular weight intermediates.

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 polyether-esters produce strong, compliant monofilament and multifilament yarns and microfibrous fabrics suitable for surgical sutures and tissue engineering, maintaining high strength retention and bioactivity, outperforming traditional polyesters in absorption and strength retention profiles.

Implementation Method 1

water up-take of at least 10 percent of their original mass

Methodology Applied
Scientific EffectOsmosis: Osmosis

Implementation Method 2

absorbable polyether-ester

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentUS8784861B2Swellable fiber- and microfiber-forming polyether-esters and applications thereof
Publication Date: 2014.07.22 POLY MED INC

AI summary

Biomedical and tissue engineering devices, such as surgical sutures and microporous scaffolds, respectively, which undergo swelling and increase in dimensions when placed in aqueous environments such as living tissues, are produced by the melt-spinning or electrostatic spinning into strong monofilament and multifilament yarns or microfibrous fabrics, respectively. Such devices are formed from especially high molecular weight crystalline polyether-esters having a minimum inherent viscosity of 0.8 dL/g and heat of fusion of at least 5 J/g, wherein the polyether-esters are made by grafting to a polyester component a polyether glycol component having a minimum molecular weight of about 1 kDa with at least one cyclic monomer.