Endothelialized silicone aneurysm models for in vitro evaluation of flow diverters

OBJECTIVE: The goal of this work was to endothelialize silicone aneurysm tubes for use as in vitro models for evaluating endothelial cell interactions with neurovascular devices. The first objective was to establish consistent and confluent endothelial cell linings and to evaluate the silicone vessels over time. The second objective was to use these silicone vessels for flow diverter implantation and assessment. METHODS: Silicone aneurysm tubes were coated with fibronectin and placed into individual bioreactor systems. Human umbilical vein endothelial cells were deposited within tubes to create silicone vessels, then cultivated on a peristaltic pump and harvested at 2, 5, 7, or 10 days to evaluate the endothelial cell lining. A subset of silicone aneurysm vessels was used for flow diverter implantation, and evaluated for cell coverage over device struts at 3 or 7 days after deployment. RESULTS: Silicone vessels maintained confluent, PECAM-1 (platelet endothelial cell adhesion molecule 1) positive endothelial cell linings over time. These vessels facilitated and withstood flow diverter implantation, with robust cell linings disclosed after device deployment. Additionally, the endothelial cells responded to implanted devices through coverage of the flow diverter struts with increased cell coverage over the aneurysm seen at 7 days after deployment as compared with 3 days. CONCLUSIONS: Silicone aneurysm models can be endothelialized and successfully maintained in vitro over time. Furthermore, these silicone vessels can be used for flow diverter implantation and assessment.