Biological and biochemical properties of the carbon composite and polyethylene implant materials

We studied the biocompatibility of the carbon composites and polyethylene materials with and without collagen or collagen and proteoglycan cover. We used the in vitro technology to study the adhesion of model cells evalution, their metabolic activity and the production of TNF-alpha as a cytokine model. Under in vivo condition, the biocompatibility of tested polymers were studied in the implantation experiment, subcutaneously in the interscapular region in the laboratory rat. We have found in the in vitro assay favorable proliferation and the smallest production of pro-inflammatory TNF-alpha cytokine in cells adherent to the hydrophobic polyethylene material coated with biological macromolecules. Using in vivo tests performed by the implantation of materials to the rat we demonstrated that the materials are not cytotoxic. The tissue capsule surrounding the implants was not significantly influenced by the type of the implant and the pre-treatment by the biological molecules. However, the foreign-body giant multinucleated cells were observed only in the vicinity of the collagen - covered hydrophobic polyethylene implant. Interestingly, while the collagen coating improved the biocompatibility of tested polymers in vitro, the inflammatory reaction against this covered materials was higher under in vivo conditions. The pre-treatment of carbon composites by both types of biological macromolecules reduced the occurrence of carbon debris in the implantation site. The tested carbon composites and polyethylene materials are not toxic. The pre-treatment of the materials by extracellular matrix components increased their biological tolerance in vitro and reduced implant wears in animal experiment, which can be important for the medical application.