IN-VITRO BIOCOMPATIBILITY TESTING OF POLYMERS FOR ORTHOPEDIC IMPLANTSUSING CULTURED FIBROBLASTS AND OSTEOBLASTS

The biocompatibility of two polymers for potential use as orthopaedic implant materials in an isoelastic hip prosthesis was investigated. Th e interactions of polyetheretherketone (PEEK) and epoxy resin polymers (with and without carbon fibre reinforcement) with both fibroblasts a nd osteoblasts were tested using cell protein, intracellular reduced g lutathione (GSH), leakage of lactate dehydrogenase and the MTT assay a s indices of cellular cytotoxicity. The epoxy resin polymer was slight ly cytotoxic to and inhibited the growth rate of fibroblasts (as asses sed by total cell protein), and depleted GSH in both cell types. In co ntrast, the PEEK material did not display overt signs of cytotoxicity and, in fact, increased osteoblast cell protein content. This suggests that, of these two materials, PEEK would be the one of choice for dev elopment of an isoelastic implant and, in view of its stimulatory effe ct on osteoblast protein content, it may encourage ingrowth of bone ar ound the prosthesis and thus minimize joint loosening.