Some Interactions of Blood with Tubular Biomaterials

Native human blood was exposed to polyethylene, poly(vinyl chloride), and Silastic tubing for varying time intervals, following which the relative degree of activation of the intrinsic coagulation system and alterations in cell counts were determined. The effects of pre-exposure of Silastic to purified albumin, high-density lipoprotein, or protein polysaccharide upon subsequent reactivity of blood with these surfaces was determined. In addition, the effects of aspirin, dextran, heparin, and Warfarin on reactivity of blood with Silastic were determined. In each case, changes in coagulation and cell counts were correlated with ultra-structural features of test surfaces following their exposure to blood. Pre-exposure of Silastic to purified proteins had relatively little effect upon subsequent reactivity with blood, while the presence of antithrombotic agents produced numerous changes.