Materials containing heparin complexing polymers, physicochemical characterization and compatibility

The wide utilization of commercial polyurethane block copolymers for biomedical application is due to their superior physical and mechanical properties and to their relatively good biocompatibility. In the new material called PUPA, poly(amido-amine) chains are directly bound to the polyurethane chains by using the reagent hexamethylenediisocyanate. PUPA material was synthesized by a two-steps condensation reaction. Two different series of PUPA (PUPA I and PUPA II) were synthesized and studied by changing the amount of the cross-linking agent, i.e. hexamethylenediisocyanate, polyurethane (in this work Pellethane 2363-80AE) and poly(amido-amine). Toxicity testing has been carried out on a mouse tumor cell line by evaluating the inhibition of cell growth and viability after putting the materials in direct contact to the cells. All PUPA materials, except for PUPA I bis and PUPA II bis, seem to cause a strong reduction in cell growth, while viability seems unaffected. The heparinized PUPA materials are not toxic: the presence of heparin on the surface improves the material biocompatibility.