Chemically Bonded Antibiotic Implant Substrates for Localized Infection Control

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Solution Overview

Problem

Current antibiotic delivery systems for orthopedic and dental implants face challenges in providing long-term, controlled release of antibiotics, as they often lead to the survival of resistant bacterial strains due to fluctuating concentrations, and systemic antibiotics are ineffective against localized infections, which can cause tissue resorption and implant failure.

Innovation Solution

Chemically binding broad-spectrum antibiotics like tetracycline and ciprofloxacin to biologically active substrates using chelating mechanisms, ensuring they remain dormant until an infection occurs, at which point the substrate dissolves, releasing the antibiotics at high, effective concentrations to combat infections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If antibiotics are released continuously from a carrier system, then initial high concentration is achieved, but concentration falls off exponentially over time leading to survival of resistant bacterial strains

Engineering Contradiction:
Improveantibiotic concentrationVSAvoidrelease duration
Core Design Contradiction:
Quantity of substanceVSDuration of action of moving object

Solution Approach 1:

The patent applies preliminary action by chemically binding antibiotics to implant surfaces before implantation, creating a reservoir that releases antibiotics in response to infection triggers (pH changes, enzymes) rather than relying on passive diffusion. This ensures high concentration is maintained at the infection site throughout the duration needed to eliminate resistant strains.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes parameter changes by designing the carrier system to respond to pH changes and enzymatic activity at infection sites. The carrier releases antibiotics when exposed to acidic pH or specific enzymes produced by bacteria, thereby maintaining high concentration dynamically rather than following exponential decay.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high local concentrations of antibiotics are used, then bacterial activity is inhibited, but activity is lost as soon as antibiotics are dissipated

Engineering Contradiction:
Improveantibiotic effectivenessVSAvoidprotection duration
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent applies self-service by designing the carrier system to automatically detect infection conditions (through pH or enzyme presence) and release antibiotics accordingly, without requiring external intervention. The system serves itself by using the infection's own biochemical environment as the trigger for antibiotic release.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements feedback by creating a system where the presence of infection (indicated by pH change or enzyme activity) directly triggers antibiotic release. The carrier system monitors the local environment and adjusts antibiotic release accordingly, ensuring effectiveness is maintained as long as infection persists.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If systemic antibiotics are administered, then broad coverage is achieved, but they cannot penetrate biofilms on implant surfaces

Engineering Contradiction:
Improveantibiotic coverageVSAvoidbiofilm barrier
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by concentrating antibiotics directly at the implant surface where biofilm forms, rather than distributing them systemically. The carrier system ensures high local concentration is achieved precisely where needed (on the implant surface), overcoming the biofilm barrier that prevents systemic antibiotic penetration.

Inventive Principle:
Principle #3Local quality

4Duration of action of moving object

If antibiotics are released over extended periods, then resistant strains may survive at low concentrations, but complete eradication is needed

Engineering Contradiction:
Improverelease durationVSAvoidinfection eradication
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The patent applies periodic action by designing the carrier to release antibiotics in response to ongoing infection conditions rather than continuous release. As long as the infection persists (maintaining acidic pH or enzyme presence), the carrier continues to release antibiotics periodically, ensuring concentration remains above the minimum effective level needed to eradicate even resistant strains.

Inventive Principle:
Principle #19Periodic action

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

This approach provides sustained, high-local-concentration antibiotic release specifically at infection sites, effectively targeting and eliminating resistant bacterial strains without depleting systemic antibiotic reserves, thereby reducing the risk of implant failure and tissue damage.

Implementation Method 1

Chemically binding broad-spectrum antibiotics like tetracycline and ciprofloxacin to biologically active substrates using chelating mechanisms

Methodology Applied
Scientific EffectChelating mechanism: Chemical Bonding

Implementation Method 2

ensuring they remain dormant until an infection occurs, at which point the substrate dissolves, releasing the antibiotics at high, effective concentrations

Methodology Applied
Scientific EffectDissolution: Solvation

Data Source

PatentEP2967799B1Systems and methods of using chemically bound antibiotics activated by infections
Publication Date: 2020.09.02 OSTEOCERAMICS
  • EP2967799B1 patent drawingFigure 1
  • EP2967799B1 patent drawingFigure 2
  • EP2967799B1 patent drawing

AI summary

Methods, devices and systems are disclosed for chemically bonding antibiotics to selected substrate materials which are not dissolved in normal physiological processes so that high local concentrations can be achieved during the inflammatory response. The antibiotics will remain permanently bonded to the substrate material until an infection occurs which releases the antibiotic in high concentrations to help control the infection. The high local concentrations may be much higher than systemic toxic levels, and can never reach toxic levels because the local dose is much less than needed to reach systemic toxicity if completely dissolved.