Biocomposites used in orthopedic applications: Trends in biocompatibility assays

Abstract

Biocompatibility assays have undergone a revolution from the early tests designed to investigate inertness of materials that were intended to remain within the patient indefinitely. With the increasing use of biodegradable materials and functional materials that actively play a role in the repair process, the complexity of the assays required to analyze their biocompatibility has also increased. This has led to a change in the definition of biocompatibility, with increasing emphasis being placed on tests designed to ensure a material generates the most beneficial tissue response, without any unwanted local or systemic effects. In essence this leads to more assays associated with function. Within this chapter, we aim to highlight the changing definition of biocompatibility and explain the biocompatibility testing process while providing some examples. Various in vivo assays will be described and their benefits and limits will be discussed. Aspects of regulation and standards will be discussed, and differences between the various assays will be explained.