Polyurethane-Based Biomaterials for Shape-Adjustable Cardiovascular Devices

A series of biostable polyurethane (PUR) formulations, including a composite containing a clay as filler, were prepared as new biomaterials for cardiovascular applications. Poly(dimethyl siloxane) and poly(tetramethylene oxide) were selected as macrodiols because of their mechanical properties and the high hydrolysis resistance they confer to PURs. 1,6-Diisocyanatohexane and 1,4-cyclohexane dimethanol were used as a diisocyariate and chain extender, respectively. The polymeric products were chemically, thermally, and mechanically characterized. Thermomechanical characterizations highlighted that some of the obtained formulations are promising materials for applications in the cardiovascular field, in particular, for the realization of annuloplastic rings in mitral valve repair.