Synthesis and Characterization of Radiopaque Shape Memory Polymer Foams

Abstract

Shape memory polymer (SMP) foams have been proposed for a variety of medical applications, including brain aneurysm embolization and occlusion of peripheral vascular malformations. While these devices provide significant advancements in treatment, such as increased volumetric filling and improved healing outcomes, one inherent limitation is a lack of visibility under x-ray fluoroscopy. Medical professionals rely on noninvasive material visualization to enable safe and effective device placement. Although metal markers can assist with SMP device placement, it is difficult to anticipate the interactions between the expanding polymer device and complicated vessel anatomy. Thus, there is a significant clinical need for the development of SMP formulations that can be observed under x-ray during expansion. Using a bulk synthesis method, a contrast agent is incorporated into the polymer composition in various molar ratios to enhance foam visibility under x-ray. This project focuses on the synthesis and characterization of the radiopaque compositions necessary to achieve clinically relevant SMP foams. Foams are characterized in terms of radiopacity, morphology, and thermomechanical properties. Successful synthesis and characterization of the radiopaque foam compositions shows whether or not the properties are within a clinically relevant range for further device development.