Hydrogel Wound Dressing Sterilization via Freezing and Radiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydrogel wound dressings are challenging to sterilize using existing methods due to their moisture content and sensitivity to thermal and radiation processes, which can compromise their absorptive properties.
Innovation Solution
The method involves applying an aqueous solution to a polymer layer comprising a hydrophobic organic matrix with hydrophilic microparticles, followed by electron beam or gamma radiation, allowing for sterilization without significant adverse effects on the dressing's moisture retention and absorptive capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gas sterilization methods (ethylene oxide or gas plasma) are used, then sterilization effectiveness is improved, but packaging options are limited and shelf life is reduced due to moisture transport through permeable packaging
Solution Approach 1:
The patent changes the physical state parameter of the hydrogel by freezing it before sterilization. This phase change from liquid to solid reduces moisture mobility and prevents water vapor transmission through packaging during gas sterilization, thereby maintaining shelf life while achieving effective sterilization.
Solution Approach 2:
The patent applies a preliminary action by freezing the hydrogel dressing before subjecting it to gas sterilization. This pre-freezing step modifies the material properties to enable subsequent sterilization without compromising shelf life, as the frozen state prevents moisture transport during the sterilization process.
2Adaptability or versatility
If steam sterilization is used, then packaging versatility is improved, but dressing properties are adversely affected due to heat application
Solution Approach 1:
The patent changes the temperature parameter by conducting sterilization at low temperatures through gas phase sterilization of the frozen hydrogel. This avoids the high temperature exposure of steam sterilization that causes degradation of the hydrogel polymer network and loss of absorptive properties.
3Adaptability or versatility
If gamma or electron beam irradiation is used, then packaging versatility is improved, but polymer properties are degraded due to crosslinking or degradation
Solution Approach 1:
The patent changes the physical state parameter by freezing the hydrogel before irradiation sterilization. This phase change reduces the mobility of polymer chains and water molecules, minimizing free radical formation and subsequent crosslinking or degradation reactions that would otherwise occur during gamma or electron beam irradiation.
4Reliability
If hydrogel dressings are sterilized in moist state, then sterilization effectiveness is improved, but absorptive capacity is significantly reduced
Solution Approach 1:
The patent changes the temperature parameter by sterilizing the frozen (cold) hydrogel rather than the moist (warm) hydrogel. This temperature parameter change reduces water mobility and prevents excessive water absorption during sterilization, thereby preserving the hydrogel's absorptive capacity while maintaining sterilization effectiveness.
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 method effectively sterilizes hydrogel wound dressings while maintaining at least 40% of their original absorptive capacity, with some embodiments retaining up to 80%, ensuring the dressings remain effective post-sterilization.
Implementation Method 1
The aqueous solution at least partially swells the hydrophilic microparticles of the polymer layer
Implementation Method 2
applying electron beam radiation to the article
Implementation Method 3
Each sterilization method has advantages and disadvantages... gamma irradiation, and electron beam irradiation
Implementation Method 4
applying gamma radiation to the article
Implementation Method 5
Each sterilization method has advantages and disadvantages... gamma irradiation
Data Source
AI summary
Methods of sterilizing articles such as wound dressings, include the steps of providing an article that includes a polymer layer, applying an aqueous solution to the polymer layer and applying electron beam radiation to the article. The polymer layer includes a hydrophobic organic matrix that includes an elastomeric polymer and hydrophilic polymeric microparticles dispersed within the elastomeric polymer. Applying the aqueous solution to the polymer layer at least partially swells the hydrophilic microparticles of the polymer layer. In some articles the polymer layer includes an elastomeric polymer, hydrophilic polymeric microparticles dispersed within the elastomeric polymer, and hydrophilic polymer particles with greater than 10 micrometers average particle size dispersed within the hydrophobic organic matrix. These articles may be sterilized by applying either electron beam or gamma radiation.