| dc.description.abstract | Shape memory polymers (SMPs) are materials with the ability to undergo geometric change in response to a stimulus, also known as the shape memory effect. This shape memory behavior enables minimally-invasive delivery of medical devices, making SMPs of interest to biomedical researchers. Our group has extensively studied thermoset polyurethane SMP foams and modifications thereof to improve device performance. These gas-blown, low-density foams demonstrate high volumetric recovery and rapid hemostasis, making them particularly desirable for embolic applications. Another SMP thermoplastic polyurethane (TPU) material was previously developed by Hearon et al. This SMP system is currently underutilized, but it is highly tunable and processable, enabling control over polymer properties and architecture.
This research provides a foundation for expanded future use of both polyurethane SMP systems (thermoset and thermoplastic) by addressing their major limitations for biomedical applications. There is a lack of inherent X-ray and MRI visibility with these polymeric materials, which can hinder device delivery and monitoring; therefore, a major goal was to modify the thermoset systems to achieve adequate visualization on X-ray and MRI modalities. Similarly, the TPU material system was modified to improve the X-ray visibility on molded parts. Drug delivery from a SMP matrix was explored for the intended use in breast cancer recurrence after tumor resection. Antimicrobial foams with modified antimicrobial triols and direct incorporation of antimicrobial agents were explored for use in hemostatic devices. Finally, in vivo use of the thermoset material is limited by its susceptibility to oxidation. Thus, the last goal was to improve the biostability of SMP thermoset foams. | |
