Current trends in biocompatibility testing.

Biocompatibility remains the central theme for biomaterials applications in medicine. It is generally accepted that this term means not only absence of a cytotoxic effect but also positive effects in the sense of biofunctionality, i.e. promotion of biological processes which further the intended aim of the application of a biomaterial. The national and international standards for testing regimes represent a lowest common denominator for such applications and do not necessarily ensure that optimal function will be achieved. The authors' thesis is that biocompatibility testing has scope for extensive development with respect to biofunctionality. The present paper reviews current trends in the in vitro aspects of biocompatibility testing. As well as a critical appraisal of the recent literature, future trends are also stressed, which the authors regard as essential for a meaningful integration of a modern biological approach into new developments in the material sciences. These include the application of modern techniques of cell and molecular biology, the concepts of tissue remodelling, hybrid organ development and encapsulated cell technology.