Shape Memory Polymer Barbed Sutures for Sustained Antimicrobial Release

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

There is a need for improved barbed sutures that can remain in vivo for extended periods with enhanced antimicrobial efficacy, requiring methods to sustain the delivery of bioactive agents effectively while minimizing the amount of antimicrobial agents used, and to promote wound healing.

Innovation Solution

The development of barbed surgical sutures with barbs made from shape memory polymers that transition from a temporary shape to a permanent shape upon implantation, releasing bioactive agents from the barb angles, which can be made from bioabsorbable or non-degradable materials, including block copolymers like polydioxanone and polylactides, to provide controlled and sustained release of antimicrobial agents and other therapeutic agents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If barbed sutures are made with conventional materials and coatings, then they provide basic wound closure, but they lack sustained antimicrobial efficacy and require higher amounts of antimicrobial agents

Engineering Contradiction:
Improveantimicrobial efficacyVSAvoidamount of antimicrobial agent
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The bioactive agent is pre-loaded within the barb angles during manufacturing, positioning the antimicrobial agent exactly where it is needed at the wound interface before implantation. This preliminary positioning ensures immediate and sustained antimicrobial protection without requiring excessive amounts of the agent.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The antimicrobial agent is delivered locally to the specific locations where barbs contact the tissue, rather than coating the entire suture. This localized delivery concentrates the antimicrobial effect at the critical wound interface, improving efficacy while reducing the total quantity of agent required.

Inventive Principle:
Principle #3Local quality

2Duration of action of stationary object

If barbed sutures remain in vivo for extended periods, then they maintain wound closure, but they risk infection and loss of antimicrobial efficacy over time

Engineering Contradiction:
Improveduration of wound closureVSAvoidinfection risk
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The shape memory barbs provide continuous mechanical retention of the suture in tissue, maintaining wound closure over extended periods. Simultaneously, the bioactive agent provides continuous antimicrobial protection as the barbs remain engaged with tissue, creating a sustained dual function that addresses both wound closure and infection prevention throughout the extended in vivo period.

Inventive Principle:
Principle #20Continuity of useful action

3Duration of action of moving object

If shape memory polymers are used for barbs, then controlled release of bioactive agents is achieved, but device complexity increases

Engineering Contradiction:
Improvecontrolled release durationVSAvoidpolymer material complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The shape memory polymer undergoes a temperature-induced parameter change, transitioning from a deformed low-temperature state during insertion to a recovered high-temperature state at body temperature. This parameter change automatically triggers the expansion of barb angles and release of the bioactive agent, providing controlled release without complex mechanical mechanisms.

Inventive Principle:
Principle #35Parameter changes

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 shape memory polymer sutures effectively extend the antimicrobial efficacy and promote wound healing by controlled release of bioactive agents, reducing the amount of antimicrobial agents needed and ensuring prolonged action, while maintaining tissue adhesion and preventing infection.

Implementation Method 1

the barbs are made from a shape memory polymer having a permanent shape which may be deformed to a temporary shape, such that barbs of the suture extend at different barb angles in the different shape configurations

Methodology Applied
Scientific EffectShape memory polymer: Shape Memory Polymer

Data Source

PatentEP2380599B1Biactive substance in a barbed suture
Publication Date: 2015.09.16 COVIDIEN LP
  • EP2380599B1 patent drawingFigure 1
  • EP2380599B1 patent drawingFigure 2
  • EP2380599B1 patent drawingFigure 3A~3C

AI summary

Barbed surgical sutures are provided which include an elongated body and a plurality of barbs extending therefrom. A bioactive agent is disposed within barb angles formed between the barbs and the elongated body. The barbs may be made from a shape memory polymer having a permanent shape which may be deformed to a temporary shape, such that barbs of the suture extend at different barb angles in the different shape configurations. The barb angles of the permanent shape may be greater than the barb angles of the temporary shape, thereby exposing and/or releasing a bioactive agent after placement in tissue.