Carbons

Abstract

The biocompatibility of carbon has long been appreciated: ancient man, for example, knew that pulverized charcoal could be placed under the skin without any apparent ill effects (Benson, 1969). The charcoal particles visibly remained indefinitely and thus allowed ancient man the means to decorate himself permanently with tattoos. However, it was not until the mid-1960s that carbon was first considered for use as a structural material in implantable prosthetic devices. During this period, a specific, imperfectly crystalline, man-made, pyrolytic form of carbon was found to be well suited for application in prosthetic heart valves. Because of the outstanding clinical success of pyrolytic carbon in long-term structural components of heart valve prostheses, carbons have assumed a prominent position in our repertoire of biomaterials and have sparked investigation of other forms of carbons for possible in vivo use. A number of these forms are listed in Table 11.1. This chapter will be devoted to a discussion of the background and historical uses of carbons in medical devices along with suggestions for future research.