Hydrogel Coating on Polymeric Medical Substrates
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Solution Overview
Problem
Existing methods for applying hydrogel coatings on polymeric medical device substrates, such as catheters, face challenges in achieving improved lubricity and wear resistance, particularly in the catheter lumen, and often require hazardous solvents and lengthy immersion times.
Innovation Solution
A method involving a priming step with a solution containing poly(ethylene glycol) diacrylate and a crosslinking agent, followed by a grafting step with a mixture of polyvinylpyrrolidone and polyethylene oxide, which provides a highly lubricious and adherent hydrogel coating without the need for hazardous solvents and reduces processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ultraviolet curing method is used to apply hydrogel coating, then the coating can be applied to polymeric substrates, but the method is difficult to apply to catheter lumen and requires primer coating and curing steps
Solution Approach 1:
The invention extracts and eliminates the UV curing step from the coating process, replacing it with a simple air-drying step. The priming solution contains peroxide that initiates polymerization upon contact with the substrate, eliminating the need for external UV curing equipment and complex multi-step processes, thereby simplifying the overall manufacturing procedure.
Solution Approach 2:
The coating composition is segmented into distinct functional components: a priming solution containing peroxide initiator and crosslinking agents, and a separate hydrogel coating composition. This segmentation allows each component to perform its specific function optimally - the priming solution prepares the surface and initiates bonding, while the coating provides the lubricious layer, simplifying the application process.
2Reliability
If conventional hydrogel coating methods are used, then biocompatible coating is achieved, but lubricity and wear resistance are insufficient
Solution Approach 1:
The invention uses a composite coating system consisting of a polymeric substrate, a priming layer formed from peroxide-initiated polymerization of crosslinking agents, and a hydrogel coating layer. This composite structure combines the mechanical strength of the substrate with the lubricious properties of the hydrogel, while the peroxide-initiated priming layer provides strong chemical bonding, achieving both biocompatibility and superior lubricity with wear resistance.
Solution Approach 2:
The invention changes the chemical parameters of the coating system by using peroxide-initiated polymerization instead of conventional UV or moisture-curing methods. This parameter change enables the formation of a highly crosslinked priming layer that provides exceptional bonding strength, allowing the hydrogel coating to maintain its lubricious properties while achieving superior wear resistance.
3Strength
If toluene priming solution is used as disclosed by Butruk et al, then coating adhesion is achieved, but hazardous solvent and lengthy immersion time are required
Solution Approach 1:
The invention converts the potentially harmful peroxide compound into a beneficial initiator for polymerization. Instead of using hazardous toluene solvent, the peroxide is dissolved in water or alcohol to create a safe priming solution that initiates polymerization upon contact with the substrate, providing strong adhesion without hazardous solvents or lengthy immersion times.
Solution Approach 2:
The invention changes the solvent parameter from hazardous toluene to safe water or alcohol, and changes the initiation mechanism from simple immersion to peroxide-initiated polymerization. This parameter change maintains strong coating adhesion while eliminating hazardous solvent exposure and reducing processing time from 10-15 minutes to a rapid polymerization process.
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 method results in a hydrogel coating with enhanced lubricity and resistance to wear, maintaining low friction forces even after multiple test cycles, and allows for efficient coating of complex substrate areas like the catheter lumen.
Implementation Method 1
a priming step wherein the polymeric substrate is contacted with a priming solution, comprising a radical source and a crosslinking agent
Implementation Method 2
Polymeric substrates, such as used in medical devices like guiding catheters, balloon catheters, urinary catheters, aspiration catheters, introducer sheaths, guidewires, access systems, thrombectomy devices, stent delivery systems, stent graft delivery systems, and heart valve delivery systems, are commonly provided with a biocompatible hydrophilic coating, or hydrogel, to reduce friction force
Data Source
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AI summary
The present invention relates to a method for providing a hydrogel coating on a polymeric substrate of a medical device comprising: a priming step wherein the polymeric substrate is contacted with a priming solution comprising 1 to 30 wt % of a polyethylene glycol diacrylate having an average molecular weight of 300 to 750 Da; a grafting step following the priming step wherein the polymeric substrate is contacted with a grafting solution, thereby providing a polymeric substrate of a medical device having a hydrogel coating.