In vitro platelet interactions with a heparin–polyvinyl alcohol hydrogel

Abstract

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/10³ μ² on PVA; 18.3 ± 4.6 plt/10³ μ² 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).