Antimicrobial Metal Oxide Layer Sustained Silver Ion Release
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Solution Overview
Problem
Soluble silver salts used for preventing microbial infections do not provide a prolonged release of silver ions, leading to frequent reapplication needs, which can be burdensome, especially for implanted medical devices.
Innovation Solution
An anti-microbial article comprising an occlusive layer, an absorbent substrate, a metal oxide layer with less than 40 wt.% non-oxidized metal, and a metal layer, designed to provide a sustained release of silver ions through controlled metal oxide formation, enhancing antimicrobial activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If soluble silver salts are used to prevent microbial infections, then anti-microbial activity is achieved, but the release of silver ions is not prolonged and frequent reapplication is required
Solution Approach 1:
The patent employs a composite layered structure consisting of a metal layer (containing silver) and a metal oxide layer (containing silver oxide). This composite material design allows the metal layer to provide initial silver ion release while the metal oxide layer provides sustained release over an extended period, thereby resolving the contradiction between achieving anti-microbial activity and prolonging the release duration.
Solution Approach 2:
The patent changes the chemical state of silver from purely metallic (in soluble salts) to a combination of metallic and oxidized forms (in the layered structure). By controlling the oxidation state and creating a gradient from metal to metal oxide, the system achieves both immediate and prolonged silver ion release, extending the duration of action while maintaining anti-microbial effectiveness.
2Reliability
If soluble silver salts are applied frequently to maintain anti-microbial effect, then continuous protection is achieved, but the process becomes burdensome and impractical
Solution Approach 1:
The patent applies preliminary action by pre-structuring the anti-microbial coating as a layered composite of metal and metal oxide before application. This pre-engineered structure is designed to automatically provide prolonged silver ion release without requiring frequent human intervention for reapplication, thus maintaining continuous protection while greatly improving ease of operation.
Solution Approach 2:
The layered metal-metal oxide structure serves itself by providing sustained silver ion release from the metal oxide layer after the initial metal layer has released its ions. This self-sustaining mechanism eliminates the need for frequent reapplication by the user, making the system both continuously effective and easy to operate.
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 article achieves a more than 4 log reduction in bacterial growth within 7 days and provides a prolonged release of antimicrobial agents, reducing the need for frequent reapplication and enhancing antimicrobial activity.
Implementation Method 1
a metal oxide layer overlaying the substrate, wherein the metal oxide layer comprises an antimicrobial metal oxide
Implementation Method 2
an absorbent substrate selected from foam, fabric, nonwoven, hydrocolloid, hydrogel, and combinations thereof
Data Source
Figure 1~2
AI summary
An article having anti-microbial effect is provided. The article includes an occlusive layer; a substrate overlaying the occlusive layer, wherein the substrate having two opposing major surfaces; a metal oxide layer overlaying the substrate, wherein the metal oxide layer comprises a metal oxide and wherein the metal oxide layer comprises less than 40 wt.% non-oxidized metal; and a metal layer overlaying the metal oxide layer.