In this paper we describe the toxicological tests done on a machinable glassceramic, prepared at the Defence Metallurgical Research Laboratory. Tests show no toxicity and biocompatibility is inferred.

Carbon in the form of pyrolytic carbon coating is used in a number of implantable medical devices. Carbon-reinforced carbon composite and other forms of diamond-like carbon coatings are being evaluated for their many potential biomedical applications. There is also a possibility of using carbon in fibre form. Though the possibility of using the fibre form of carbon in skeletal and dental implants has been recognized, a detailed study of tissue reaction to carbon fibre has not been reported so far. In this paper, we describein vitro andin vivo evaluation of carbon fibre in bone and muscle. Good cell and tissue biocompatibility of the material was observed in bone and muscle. New bone was present in contact with the fibres. Results of this study indicate that carbon fibre has potential in non-load bearing applications, such as skeletal repair and as ligament prosthesis.

The technological orientation of current medical practice is reflected in the effective utilization of a number of diagnostic and therapeutic devices. Synthetic and natural biomaterials alone or in combination form the basis for development of such devices that are in contact with different tissues. The effect of materials on tissues andvice versa needs to be understood to ensure safety and effectiveness of the devices. This calls for biological evaluation of materials and devices, in addition to a spectrum of recommended toxicological testing of materials depending upon the duration and the type of tissue in contact with. Besides being non-toxic, the material is required to meet the functional requirements with the appropriate host response which is termed as biocompatibility.

This paper reviews the evolution and the requirements of biomaterials. Thein vitro andin vivo evolution methodologies are highlighted based on our experience in developing blood bag, dental composite, hydroxyapatite and fibrin glue. The requirements of biomaterials in the current context of advances in the fields of tissue engineering and biomimetics is outlined.