Interaction of human α‐thrombin with artificial surfaces and reactivity of adsorbed α‐thrombin

Abstract

Thrombin adsorbed onto Cuprophane or poly(vinyl chloride) (PVC) was shown to be inactive with respect to amidase activity. Desorbed thrombin from these two artificial surfaces showed only low amidase activity. However, in the presence of albumin, the surface‐bound thrombin appeared to exhibit increased amidase activity. This apparent activity may be due to the action of thrombin displaced from the surfaces by albumin. Thrombin bound to Cuprophane or PVC was shown to be capable of reacting with antithrombin III (AT III) only in the presence of heparin. On the other hand, AT III bound to Cuprophane or PVC was unable to react with thrombin in either the absence or presence of heparin. Fibrin formation on or at surfaces was demonstrated by phase contrast microscopy when Cuprophane or PVC pretreated with thrombin and carefully rinsed was incubated in a fibrinogen solution. This fibrin formation is time dependent and likely is the result of direct interaction of adsorbed thrombin with fibrinogen in solution. Glass, Cuprophane, and PVC pretreated with thrombin were shown to attract more platelets than respective untreated surfaces. The enhancing effect of adsorbed thrombin on platelet adhesion was similar to the enhancing effect of adsorbed fibrinogen. Thrombin adsorbed onto PVC and crosslinked by glutaraldehyde treatment was shown to be antigenically active with a 125I‐labeled monospecific antithrombin IgG produced in rabbits. No other plasma proteins adsorbed singly or from plasma or serum onto PVC reacted significantly with the antithrombin IgG preparation. The possible significance of these observations is discussed.

Quantification of Hydrophobicity of Heparin-Treated Polyvinylchloride Tubing

“…The surfaces of 16 different polymers were characterized using static secondary ion mass spectroscopy, electron spectroscopy for chemical analysis, and contact angle measurements of several liquids. This study found a high degree of positive correlation between fibrinogen binding and a high dispersive component of surface energy was also observed to correlate with fibrinogen retention at the material surface, indicating stronger interactions (6). The results of our study suggest that 3M and Carmeda heparin-coated PVC tubings may offer the most biocompatible luminal surface with the least amount of fibrinogen binding and retention.…”

“…Every different type of synthetic material will have a characteristically different layer of adsorbed proteins at the blood-material interface. Studies have shown a clear correlation between the hydrophobicity of synthetic surfaces an their ability to bind and retain fibrinogen (6). Numerous studies have shown that fibrinogen is a primary component of the adsorbed protein layer (7)(8)(9).…”

Voltammetric assay of thrombin adsorbed on the carbon paste electrode

“…On some surfaces, like polymers [14,15], thrombin loses almost all of its catalytic activity. On glass Mizutani observed that activities increased [16].…”

The Relationship Between Acute-Phase Circuit Occlusion and Blood Calcium Concentration in an Ex Vivo Continuous Renal Replacement Therapy Model

“…No significant difference was observed between the blood test performed two points before occlusion and that performed before occlusion for ALB (Figure 6 ), although a trend towards a decrease at all calcium injection flow rate groups was observed. This is likely attributed to an adsorption reaction of ALB on polyvinyl chloride, which is used in blood circuits and seat bags [ 20 , 21 ]. Additionally, polyvinyl chloride transports small amounts of CO 2 gas [ 22 - 23 ], which might have affected the pH of the blood, leading to charge changes and ALB measurement errors.…”