Comparative biological tests on segmented polyurethanes for cardio-vascular applications

In order to select a candidate segmented polyurethane (SPU) elastomer for the preparation of cardio-vascular prostheses, a series of biological tests (namely haemolysis, aPTT and PT coagulation tests, cytotoxicity, human endothelial cells seeding) was carried out on five commercially available biomedical polyurethanes. The tests were performed on solvent cast samples, from THF (Cardiothane 51, Pellethane 2363 80A, Estane 5714 Fl, and Estane 58810), or DMAC (Biomer). All the materials were sterilized by γ-irradiation before being tested. From the results obtained all the polyurethanes used in this study were shown to be devoid of toxicity towards blood (as proved by haemolysis and coagulation time tests) or blood cells (as proved by cytotoxicity and cell adhesion assays). A clear difference among the tested copolymers didn't stand out under our test conditions, although Cardiothane, possibly due to its physico-chemical characteristics, was less effective in promoting endothelial cell adhesion.