Highly Porous Shape Memory Nanocomposites for Applications in Biomedical Devices

Abstract

This paper presents the novel development of highly porous carbon nanotube (CNT)/shape memory polymer (SMP) nanocomposites for potential endovascular treatment of intracranial aneurysms (ICAs). Intracranial aneurysm is a cerebrovascular disorder that can significantly weaken the wall of a brain artery, resulting in a localized dilation of the blood vessel with risk of rupture and subarachnoid bleeding. Current therapeutic options include surgical clipping and endovascular coil embolization. Clipping of intracranial aneurysms is invasive, and, therefore, it has gradually been replaced by non-invasive endovascular embolization. Recent studies have shown that aneurysmal recanalization and incomplete occlusion are still emerging clinical challenges in endovascular coil embolization. Therefore, there is an urgent need to develop new medical devices and surgical procedure to treat intracranial aneurysms with improved long-term outcomes. CNT/SMP nanocomposites are fabricated by directly coating CNTs on sugar particles before fabricating the sugar template for porous nanocomposites. Pristine SMP prepolymer is infiltrated into the pores of sugar template. All the sugar is dissolved in water after the fully curing of PDMS, resulting in SMP based nanocomposites with well dispersed CNTs. The porous nanocomposites are characterized to identify key parameters, such as electrical resistivity and shape memory capability. A resistive-heating mechanism is developed to trigger shape recovery of the nanocomposites. The results of this work will lay a solid foundation for our subsequent development of new personalized biomedical devices to treat ICAs using a catheter-based endovascular embolization procedure.