Surface Modifying Additives Reduce Thrombogenicity: An In Vitro and Clinical Evaluation

To improve the biocompatibility of biomaterials a new surface treatment has been described based on the addition of polysiloxane containing copolymers to the base polymer resin (surface modifying additives). In an in vitro and a clinical study, we compared the thrombogenicity of polyvinyl chloride (PVC) to PVC with these surface modifying additives (SMA). In the in vitro study, adsorption of thrombin and fibrinogen, binding of platelets and platelet release were measured on the tubing and were found reduced on SMA-PVC. For the clinical study, we examined tubing material and blood collected after cardiopulmonary bypass (CPB). Onto the tubing, the binding of platelet receptor GpIIIa, and the adsorption of fibrinogen was measured. The binding of GpIIIa on the arterial SMA tubing was significantly less than on the arterial PVC tubing (p \u3c 0.02). In the blood collected during the operation, the concentrations of ß-thromboglobulin and prothrombin fragment 1 + 2 were higher in samples obtained from control patients (p \u3c 0.05)