General Concepts of Biocompatibility

Abstract

The host responses to biomaterials are extremely varied, involve a range of different mechanisms and are controlled by factors that involve characteristics of host, material and surgical procedure. These responses themselves constitute a significant component of the phenomenon of biocompatibility. In this section, the broad concepts of biocompatibility are critically reviewed with particular reference to the role that the human host response plays in determining the performance of the biomaterial and of the device in which it is used. Particular emphasis is given to the influence of biocompatibility in the clinical applications of devices. It should be remembered, however, that biocompatibility phenomena are extremely difficult to interrogate remotely or to study in an active way, so that accurate information of the details of biomaterial-human tissue interactions is not readily available. As Black (1) has pointed out with reference to observations on the host response in general, we are usually limited to detecting events long after they have occurred by examining end-points, usually histopathologically, after the host is dead. This is largely the case with experiments on biocompatibility in animals, but is an even more relevant observation with the human clinical experience. All comments in this section must therefore be interpreted with this in mind.