Endoprosthesis Coating with Segmented Antimicrobial Layers

Solution Overview

Problem

Endoprosthesis components face challenges with microorganism attachment and acceptance in the human body, particularly during invasive procedures and large surface area contact, where existing hard material coatings release antimicrobial silver too slowly to be effective against initial microbial loads.

Innovation Solution

An endoprosthesis component design featuring an intermediate layer accessible from the outside, combined with a hard outer layer containing refractory metal nitrides, oxynitrides, or oxides, and incorporating silver and/or copper, which allows for immediate release of a higher antimicrobial dose post-implantation through a porous or microstructured surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a hard material coating (nitride, oxynitride, or oxide based on refractory metal) is applied to the endoprosthesis component surface, then mechanical properties and biocompatibility are improved, but antimicrobial effectiveness is worsened due to slow silver release

Engineering Contradiction:

Improvemechanical propertiesVSAvoidantimicrobial effectiveness

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The coating is divided into two distinct layers: an outer hard material layer (nitride, oxynitride, or oxide based on refractory metal) providing mechanical strength and biocompatibility, and an inner intermediate layer containing silver particles that provides antimicrobial protection. This segmentation allows each layer to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The intermediate layer with silver particles is applied beforehand, directly onto the endoprosthesis component surface before the outer hard material layer is deposited. This preliminary positioning ensures that silver particles are already in place to provide immediate antimicrobial action when the implant is inserted, rather than relying on slow diffusion through a dense outer layer.

Inventive Principle:

Principle #10Preliminary action

2Duration of action of stationary object

If silver particles are incorporated into the hard material layer, then long-term antimicrobial action is improved, but immediate antimicrobial effectiveness is worsened due to slow release rate

Engineering Contradiction:

Improvelong-term antimicrobial actionVSAvoidsilver release rate

Core Design Contradiction:

Duration of action of stationary objectVSSpeed

Solution Approach 1:

The coating is divided into two distinct layers: an outer hard material layer (nitride, oxynitride, or oxide based on refractory metal) providing mechanical strength and biocompatibility, and an inner intermediate layer containing silver particles that provides antimicrobial protection. This segmentation allows each layer to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The intermediate layer acts as a mediator between the endoprosthesis component and the outer hard material layer. It contains the silver particles and allows them to be released effectively, while the outer layer provides the necessary mechanical properties. The intermediate layer facilitates the release of silver particles without requiring them to diffuse through the dense hard material structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Strength

If the entire surface is covered with outer layer, then mechanical durability is improved, but antimicrobial accessibility is worsened

Engineering Contradiction:

Improvemechanical durabilityVSAvoidmicroorganism attachment

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The coating is divided into two distinct layers: an outer hard material layer (nitride, oxynitride, or oxide based on refractory metal) providing mechanical strength and biocompatibility, and an inner intermediate layer containing silver particles that provides antimicrobial protection. This segmentation allows each layer to optimize its specific function without compromising the other.

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

Enhances antimicrobial action by providing immediate infection control and long-term protection against microorganisms, combining mechanical durability with effective biocompatibility and antimicrobial properties.

Implementation Method 1

oxidize the surface of an implant, made of metal or a metal alloy, and to provide the resulting hard material layer with silver particles

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS8845751B2Endoprosthesis component

Publication Date: 2014.09.30 WALDEMAR LINK GMBH & CO KG

AI summary

An endoprosthesis component and a method for producing an endoprosthesis component is disclosed. The endoprosthesis component comprises a body predefining the shape of the endoprosthesis component. On surface portions with which the endoprosthesis component in the implanted state is in contact with human tissue, the body is covered with an outer layer which comprises a nitride, an oxynitride or an oxide based on a refractory metal and which contains silver and/or copper. An intermediate layer is arranged between the outer layer and the body in such a way that parts of the intermediate layer are accessible from the outside. The endoprosthesis component enables generation of a long-term antimicrobial action with the outer layer and, in addition, action on the surrounding tissue from the intermediate layer.