ProNectin F-grafted-ethylene vinyl alcohol copolymer (EVAL) as a liquid type material for treating cerebral aneurysm—An in vivo and in vitro study

The authors aimed to develop a liquid material for embolization of aneurysms. In vitro and in vivo performances of the new embolic material were examined by cell culture and using an aneurysm model made in common carotid arteries (CCAs) of adult rats. Engineered protein ProNectin F (PnF), which contains 13 sites of an arginine-glycine-aspartic acid (RGD), was grafted onto ethylene vinyl alcohol copolymer (EVAL-g-PnF). The liquid material, EVAL-g-PnF dissolved in DMSO, was infused into an aneurysm model. The blood segments were harvested 2, 5, and 14 days and examined histologically. A number of bovine coronary artery endothelial cells became able to attach to and form cobblestone-like islands on the EVAL by incorporating PnF. The aneurysm model infused with the EVAL-g-PnF solution revealed that the aneurysm lumen was filled with proliferated fibroblasts and macrophages. On the other hand, the aneurysm model treated with unmodified EVAL showed that the cavity was almost filled with EVAL mass and that fibroblasts and macrophages filled a narrow space between the EVAL mass and the cavity wall. The results indicate that EVAL-g-PnF could be more suitable for reorganizing the cavity of an aneurysm than native EVAL.