PLATELET-ADHESION TO NOVEL PHOSPHOLIPID MATERIALS - MODIFIED PHOSPHATIDYLCHOLINE COVALENTLY IMMOBILIZED TO SILICA, POLYPROPYLENE, AND PTFE MATERIALS

Based on the premise of achieving blood compatibility through mimickin g the chemical constituents of the biologically inert surface of the u nactivated platelet membrane, a process was developed that entails the covalent grafting of modified phosphatidylcholine molecules to materi als including silica, polypropylene, and polytetrafluoroethylene (PTFE ) polymer films. These materials were characterized using x-ray photoe lectron spectroscopy (XPS) and contact-angle measurements. The phospha tidylcholine-containing materials (PC materials) were used as substrat es in the platelet-adhesion assays and were subjected to enzymatic deg radation evaluation. Phosphatidylcholine-grafted silica materials do n ot support platelet adhesion. In addition the number of adherent plate lets correlate with the amount of grafted phospholipid present, as ind icated by the phosphorus/carbon ratio obtained by XPS analysis. Platel et adhesion to phosphatidylcholine-grafted polypropylene and PTFE was inhibited 80% and 90%, respectively, when compared with platelet adhes ion to unmodified polypropylene and PTFE. (C) 1996 John Wiley & Sons, Inc.