Covalent SMAMP Antimicrobial Polymer Attachment

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Solution Overview

Problem

Current antimicrobial coatings for medical implants and devices are inadequate due to issues such as leaching of antimicrobial agents, short-term efficacy, lack of specificity towards certain bacteria, and toxicity to mammalian cells, leading to challenges in preventing biofilm formation and infections.

Innovation Solution

Development of synthetic mimics of antimicrobial peptides (SMAMPs) with molecular weights over 100,000 g/mol, covalently attached to surfaces using ring-opening metathesis polymerization, allowing for controlled antimicrobial activity and long-term effectiveness without leaching, while maintaining selectivity towards bacterial cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If traditional antimicrobial coatings are used on medical implants, then antimicrobial activity is achieved, but the coatings suffer from leaching of antimicrobial agents and short-term efficacy

Engineering Contradiction:
Improveduration of antimicrobial activityVSAvoidleaching of antimicrobial agents
Core Design Contradiction:
Duration of action of moving objectVSLoss of substance

Solution Approach 1:

The antimicrobial polymer is covalently attached to the implant surface before implantation, creating a permanent antimicrobial barrier that cannot leach. This preliminary covalent bonding ensures long-term efficacy by preventing the antimicrobial agent from detaching or degrading in the body environment.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A covalent bond acts as an intermediary between the implant surface and the antimicrobial polymer, creating a stable connection that prevents leaching. This chemical bond serves as a mediator that anchors the polymer firmly to the surface while maintaining its antimicrobial functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If broad-spectrum antimicrobial polymers are used, then activity against many pathogens is achieved, but toxicity to mammalian cells occurs

Engineering Contradiction:
Improveantimicrobial activityVSAvoidtoxicity to mammalian cells
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The polymer structure incorporates specific local features (facial amphiphilicity with charged groups) that create selective interaction with bacterial cells. The charged groups and amphiphilic character are localized in specific regions of the polymer chain, enabling differential recognition and interaction with bacterial versus mammalian cells.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The polymer's molecular weight is increased to greater than 100,000 g/mol, which changes the physical parameters of the antimicrobial agent. This high molecular weight, combined with facial amphiphilicity, alters the interaction mechanism to be more selective for bacterial cells while reducing non-specific toxicity to mammalian cells.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If low molecular weight SMAMPs are used, then antimicrobial activity is achieved, but efficacy against certain bacteria like S. aureus is reduced

Engineering Contradiction:
Improveantimicrobial activityVSAvoideffectiveness against different bacteria
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The molecular weight parameter is optimized to be greater than 100,000 g/mol, which enhances the polymer's ability to interact with and disrupt bacterial cell membranes. This parameter change improves effectiveness against Gram-positive bacteria like S. aureus while maintaining activity against other pathogens.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The polymer combines multiple functional elements (charged groups, hydrophobic and hydrophilic regions, high molecular weight) into a composite structure that provides broad-spectrum antimicrobial activity. This composite architecture enables effective interaction with diverse bacterial cell membranes while maintaining selectivity.

Inventive Principle:
Principle #40Composite materials

4Duration of action of stationary object

If covalent attachment of polymers to surfaces is implemented, then long-term effectiveness without leaching is achieved, but manufacturing complexity increases

Engineering Contradiction:
Improvelong-term effectivenessVSAvoidmanufacturing complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The polymer structure is segmented into distinct functional regions (charged groups, hydrophobic segments, hydrophilic segments) that can be independently optimized. This segmentation allows for modular synthesis approaches and facilitates the covalent attachment process by providing specific reactive sites on the polymer chain.

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 SMAMPs provide sustained antimicrobial activity with high specificity to bacterial cells, significantly reducing biofilm formation and infection risk on medical implants, while being non-toxic to mammalian cells, thus enhancing the safety and efficacy of medical devices.

Implementation Method 1

substrates comprising covalently attached antimicrobial polymers and preferably obtained by ring opening metathesis polymerization (ROMP)

Methodology Applied
Scientific EffectRing-opening metathesis polymerization: Chemical Bonding

Data Source

PatentEP2471827B1Covalently attached antimicrobial polymers
Publication Date: 2013.09.04 UNIVERSITATSKLINIKUM FREIBURG
  • EP2471827B1 patent drawingFigure 1
  • EP2471827B1 patent drawingFigure 2
  • EP2471827B1 patent drawingFigure 3

AI summary

The present invention relates to substrates comprising covalently attached antimicrobial polymers, which act as synthetic mimics of antimicrobial peptides (SMAMPs) and are preferably obtained by ring opening metathesis polymerization (ROMP). The inventive antimicrobial polymers exhibit a molecular weight of more than 100,000 g mol-1 and are preferably covalently attached to the surface of a substrate, e.g. an implant, a medical device, medical equipment or a (tissue-supporting) biomaterial, etc. Covalent bonding may be carried out using a photoreactive crosslinker but also "grafting onto" or "grafting from". The present invention is also directed to uses of the inventive antimicrobial polymers as defined herein, e.g. for antimicrobially coating a surface of such a substrate with a layer of the inventive antimicrobial polymer.