Biocompatibility and interfacial phenomena

Abstract

Innovation in the field of biomedical technology, involving artificial organs, separation techniques, cell culture and various diagnostic procedures requires the research and development of new materials. These biomaterials must not only meet technological and non-toxicity criteria but must also present a high level of biocompatibility. The latter property depends essentially on interfacial phenomena, since it is through the processes of protein adsorption and cell adhesion that interactions between the material and its biological environment come into play. An illustrative example is the development of haemocompatible materials. The lack of haemocompatible materials represents a real gap in the realization of artificial organs which are to be brought into contact with blood. All synthetic materials possess properties which are able to trigger the coagulation mechanisms. The key events are the adsorption of plasma proteins and the adhesion of blood platelets. Rapid adsorption of proteins leads to the formation of a proteinaceous interface whose composition and structure are strongly dependent on the interactions of the adsorbed molecules with the material. It is generally accepted that it is the changes in adsorbed protein conformation which, by exposing enzymatic sites and providing adhesion sites for platelets, constitute the intitial phase of blood coagulation activation. Thus, the development of haemocompatible materials requires a better understanding of the clotting phenomena initiated at interfaces and of the laws which govern protein adsorption and cell adhesion in relation to the superficial chemical and physical structure of biomaterials.