Systemic and Immune Toxicity of Implanted Materials

Medical implants are composed of a large range of materials including metals, metallic alloys, plastic polymers, ceramics, hydrogels, and composites. In addition, the implants are often fixed into tissues with glues or cements that contain additional potentially toxic compounds. Before they are clinically and commercially viable, all materials, devices, and their degradation by-products must meet regulatory standards for biocompatibility and prove to be nontoxic. International and national regulatory agencies define biocompatibility for any sterile or nonsterile device that comes into direct or indirect contact with the human body as the potential for unacceptable adverse biological responses resulting from the contact. This chapter will discuss factors creating risk of dose-dependent local and systemic exposures to devices and their constituents, the potential toxicities of these constituents, and mechanisms for generating systemic and hypersensitivity reactions caused by device-derived metals, chemicals, and composites.