Antimicrobial Polyurethane Resins via In-Situ Silver Ion Incorporation
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Solution Overview
Problem
The widespread use of polymeric materials in medical devices leads to foreign body-induced infections due to bacterial adhesion and biofilm formation, which are costly and challenging to treat, and existing methods for incorporating antimicrobial agents into these materials are complex and costly, often requiring secondary compounding or coating steps.
Innovation Solution
Incorporating silver ions associated with carriers like zirconium phosphate or water-soluble silicates into polyurethane resin compositions during synthesis to create antimicrobial polyurethane compositions that inhibit bacterial adhesion and biofilm formation, eliminating the need for secondary processing steps and ensuring long-lasting antibacterial properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If antimicrobial agents are incorporated into polymeric medical devices, then bacterial adhesion and biofilm formation are inhibited, but the complexity and cost of manufacturing increases due to secondary compounding or coating steps
Solution Approach 1:
The patent combines the antimicrobial agent with the polymeric material during the primary polymerization process, merging two separate functions (structural polymer and antimicrobial agent) into a single integrated material system. This eliminates the need for separate compounding or coating steps, thereby reducing manufacturing complexity while maintaining antimicrobial efficacy.
Solution Approach 2:
The antimicrobial agent is incorporated into the polymeric material during the polymerization process itself, rather than adding it later as a secondary step. This preliminary incorporation ensures uniform distribution and stable integration of the antimicrobial agent within the polymer matrix from the outset, simplifying subsequent manufacturing processes.
2Reliability
If organic antimicrobial agents are used, then bacterial adhesion is inhibited, but heat stability is poor leading to degradation during manufacturing
Solution Approach 1:
The patent modifies the chemical structure of the antimicrobial agent by incorporating it during polymerization, changing its physical and chemical parameters to achieve both antimicrobial activity and heat stability. The integration process alters the molecular environment of the antimicrobial agent, enabling it to withstand manufacturing temperatures while maintaining biological activity.
3Manufacturing precision
If antimicrobial additives are added during polymer synthesis, then uniform dispersal is achieved, but the additive must be chemically non-reactive to avoid interference with synthesis
Solution Approach 1:
The patent uses the polymeric chain itself as an intermediary carrier that incorporates and protects the antimicrobial agent during synthesis. The polymer matrix acts as a medium that allows uniform distribution of the antimicrobial agent while its chemical structure provides compatibility with the synthesis process, preventing harmful reactions.
4Reliability
If silver ions are added directly into the resin, then antimicrobial properties are imparted, but the resin discolors upon exposure to heat, humidity and light
Solution Approach 1:
The patent creates a composite material system where silver ions are integrated within the polymeric matrix during polymerization. This composite structure provides the antimicrobial properties of silver while the polymer matrix protects the silver from environmental factors like heat, humidity, and light, preventing discoloration and maintaining both antimicrobial efficacy and aesthetic appearance.
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 antimicrobial polyurethane compositions effectively reduce bacterial colonization and biofilm formation on medical devices, providing a stable and non-leaching antimicrobial surface that significantly decreases the incidence of infections and associated costs, with high efficacy against a wide spectrum of bacteria.
Implementation Method 1
The broad spectrum of biocidal activity of silver ions is 'oligodynamic' and includes anti-bacterial, anti-fungal and anti-viral activity. The silver ions bind to sulfhydryl groups in enzyme systems and interfere with the transmembrane energy transfer and electron transport in bacterial microorganisms.
Implementation Method 2
Silver ions also bind to the DNA of bacterial and fungi thereby increasing the stability of the bacterial double helix and inhibiting proliferation.
Implementation Method 3
At least one silver ion associated with a carrier may be added to the reaction prior to the complete polymerization. The carrier associated with the silver ion may be a phosphate (such as zirconium phosphate)...
Implementation Method 4
The invention provides novel polyurethane resin compositions... the reaction product of a polyisocyanate, a polyol and a multihydroxyl alcohol or polyamine
Data Source
AI summary
The present invention provides novel antimicrobial polyurethane compositions having excellent mechanical and biocompatibility properties, and methods to prepare them. The antimicrobial polyurethane compositions include a homogenous distribution of silver ions by incorporating this antimicrobial agent into the composition prior to the complete polymerization of the polyurethane. In preferred embodiments, the silver ion is associated with a carrier, such as zirconium phosphate or soluble glass powder. The present invention also includes components made from the antimicrobial polyurethane compositions, such as medical devices.