In vitro platelet interactions with a heparin-polyvinyl alcohol hydrogel

No difference in in vitro platelet reactivity was found between an immobilized heparin containing hydrogel (heparin-PVA) and the hydrogel without heparin (PVA), in a variety of experimental assays. There was no significant difference between the heparin-PVA and PVA coated polyethylene tubing in the number of 51Cr-labeled platelets, the extent of 14C serotonin release by the adherent platelets or in the degree of platelet count decrease after 1 h exposure to citrated canine whole blood in a Chandler loop system. Furthermore, adhesion and release values were lower than those observed with the uncoated polyethylene tubing (e.g., 9.3 +/- 4.3 plt/10(3) microns 2 on PVA; 18.3 +/- 4.6 plt/10(3) microns 2 on polyethylene). There was also no significant difference between heparin-PVA and PVA in bead column retention values with canine blood and with the previously reported washed human platelet adhesion/release values. Thus there appears to be no effect of the immobilized heparin by itself on the in vitro interactions of PVA with platelets, with the reactivity towards platelets dominated by that of the underlying substrate (i.e., PVA).