ABSTRACT
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 F1, and Estane 58810), or DMAC (Biomer). All the materials were sterilized by gamma-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.
Subject(s)
Blood Vessel Prosthesis , Heart Valve Prosthesis , Polyurethanes/toxicity , Animals , Cattle , Cell Adhesion , Cells, Cultured , Cytotoxicity Tests, Immunologic , Endothelium , Hemolysis , Humans , Materials Testing , Partial Thromboplastin Time , Prothrombin TimeABSTRACT
Differently terminated poly(amidoamine) (PAA) oligomers were grafted on the surface of poly(ether urethane amide)s (PEUAm), with fumaric or maleic acid moieties. The grafting reaction was Michael-type addition of amino groups to activated double bonds in the PEUAm backbone. PAAs having primary amino, or secondary amino end-groups were directly grafted on the surface of PEUAm sheets. For vinyl-terminated chains an alpha, omega amino-polyether spacer was introduced initially, following the same addition mechanism. Ungrafted and grafted materials were characterized, besides other analytical techniques, by ATR FT-IR spectroscopy. The heparin adsorption on PEAUm films was analysed after its elution from heparinized samples, quantified by coagulation tests (aPTT), and related to the presence of the PAAs chains grafted on to the surface. Results indicate that PAA-grafted PEUAm elastomeric biomaterials, display enhanced heparin adsorption abilities.
