title: In vivo assessment in sheep of thromboresistant materials by determination of platelet survival.
abstract: The thromboresistance of 13 potentially blood-compatible polymers was assessed in sheep by determining survival of 51Cr-labeled platelets. Polymer tubing (120-150 cm x 2.0-2.3 mm i.d.) coiled around the neck was incorporated into the circulation through silicone rubber connectors as a carotid artery-external jugular vein shunt. The mean platelet half-life in control animals ("shunt control") was 78.2 +/- 2.8 (SEM) hours. Eleven of the 13 polymers tested significantly shortened platelet half-life. Polyvinyl chloride (T1/2 = 45.4 +/- 3.0 hours), polyperfluoro ethylene (T1/2 = 47.0 +/-1.6 hours), and a polymethylacrylate (PMA)/acrilonitrile copolymer (T1/2 = 50.7 +/- 7.0 hours) produced the greatest shortening. Only silica-free polydimethyl siloxane (T1/2 = 74.7 +/- 4.9 hours) and PMA (T1/2 = 81.5 +/- 3.4 hours) were indistinguishable from shunt controls. Pretreatment of PMA tubing with autologous plasma in a paired trial significantly increased platelet half-life (P less than 0.05 vs. untreated PMA). This system offers an economical, reproducible, sensitive, and biologically relevant method for assessment of the reactivity of artificial surfaces with platelets.
mesh_terms: D000818:Animals; D001777:Blood Coagulation; D001792:Blood Platelets; D002470:Cell Survival; D004129:Dimethylpolysiloxanes; D005260:Female; D006207:Half-Life; D008297:Male; D011109:Polymethacrylic Acids; D011137:Polystyrenes; D011138:Polytetrafluoroethylene; D011140:Polyurethanes; D011143:Polyvinyl Chloride; D012756:Sheep; D012826:Silicone Elastomers; D013499:Surface Properties
chemical_list: D004129:Dimethylpolysiloxanes; D011109:Polymethacrylic Acids; D011137:Polystyrenes; D011140:Polyurethanes; D012826:Silicone Elastomers; D011138:Polytetrafluoroethylene; D011143:Polyvinyl Chloride