Effects of Sterilization on Shape Memory Polyurethane Embolic Foam Devices

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Medical Device Engineering

Background:

• Polyurethane shape memory polymer (SMP) foams are utilized in embolic medical devices for minimally invasive applications.
• SMPs exhibit shape recovery triggered by external stimuli like heat or water.
• Sterilization of SMP medical devices is challenging due to high temperature/humidity requirements of traditional methods.

Purpose of the Study:

• To investigate the suitability of nontraditional ethylene oxide (ntEtO) gas sterilization and electron beam (ebeam) irradiation for SMP medical devices.
• To evaluate the impact of these sterilization methods on the thermomechanical properties and functionality of SMP foams.

Main Methods:

• Polyurethane SMP foams were subjected to ntEtO gas sterilization.
• Polyurethane SMP foams were subjected to ebeam irradiation.
• Thermal characterization (e.g., glass transition temperature) and material characterization were performed on sterilized samples.

Main Results:

• Nontraditional ethylene oxide (ntEtO) gas sterilization significantly decreased the glass transition temperature of the SMP foams.
• Electron beam (ebeam) irradiation resulted in minimal changes to the thermomechanical integrity of the bulk foam.
• Device functionality was maintained in ebeam-sterilized samples.

Conclusions:

• Electron beam irradiation is a promising sterilization method for polyurethane SMP medical devices, preserving material integrity and functionality.
• Nontraditional ethylene oxide sterilization negatively impacts the properties of SMP foams, posing challenges for their use in medical devices.