Development and Evaluation of a Nanometer-Scale Hemocompatible and Antithrombotic Coating Technology Platform for Commercial Intracranial Stents and Flow Diverters

An intracranial aneurysm is a local dilation of an artery in the cerebral circulation and can be endovascularly treated with two types of medical devices known as intracranial stents or flow diverters-both are metallic devices that help redirect blood from the diseased arterial segment; yet the placement of intracranial devices in the cerebral circulation mandates the adjunctive administration of dual antiplatelet pharmaceuticals to the patient to minimize thromboembolic events, despite being associated with increased patient risk. We present a new multilayer, nanometer-scale coating technology platform suitable for commercial intracranial flow diverters to minimize the use of dual antiplatelet therapy in the elective setting and expand the use of intracranial devices in the acute setting of ruptured intracranial aneurysms. A combination of qualitative and quantitative characterization techniques including scanning electron microscopy, ellipsometry, confocal microscopy, X-ray photoelectron spectroscopy, and focused ion beam milling coupled with scanning electron microscopy were used to assess the composition, uniformity, and thickness of each coating layer on commercially available flow diverting devices. Overall, the coating was found to be relatively uniform, less than 50 nm thick, and conformal to device microwires. X-ray photoelectron spectroscopy data further indicates the developed nanoscale coating technology can be modified for use as a platform for the attachment of human recombinant thrombomodulin, a naturally occurring glycoprotein with antithrombotic functionality. The in vitro thrombin generation capacity of commercial intracranial flow diverters coated with the technology was assessed using the calibrated automated thrombogram assay; further, platelet and fibrin deposition on coated commercial flow diverters was assessed ex vivo via a primate arteriovenous shunt model. The in vitro and ex vivo test results suggest potential hemocompatible and antithrombotic properties.

Duke Scholars

Author David Hasan Neurosurgery