The role of surface thermodynamics in thromboresistance of biomaterials

A thermodynamic approach to the problem of platelet adsorption out of a suspension on to a smooth and homogeneous solid surface is developed. The interfacial tension values required may be estimated from contact angle data by means of an equation of state relation. According to the thermodynamic approach the functional dependence of platelet adsorption on surface tension of the solid differs according to whether the surface tension of the platelets is smaller or larger than the surface tension of the liquid in which they are suspended. The implications of this thermodynamic approach in situations where plasma proteins are present and the biomaterials surfaces may be heterogeneous and rough are discussed. Previous analyses using the critical surface tension of wetting and other surface-related parameters are compared with the thermodynamic analysis given here.