In Vitro Cytocompatibility Tests

While cytotoxicity involves negative criteria such as cellular alterations, cell death, hampered growth etc. then cytocompatibility is more vague but suggests positive criteria. A material will be considered as cytocompatible if both structure and functions of the tissue in direct contact with it remain unchanged. The maintenance of these functions depends directly upon the quality of the material surface. Thus a material may induce reorganisation of a tissue without exhibiting cellular damage, but the previous (original) structure and functions will be lost. Therefore research and development of biomaterials may provide surface properties of the material which satisfy these requirements. Most research on blood contacting material is concerned with this aspect. As non-thrombogenicity is a main property of the vascular endothel recent studies aim at finding materials which enhance neoendothelialization. Cell culture experiments may be carried out with endothelial cells and with tissues after a control of the structural and functional state. Tests of these properties are described in the following.