Abstract
To inhibit the oxidation in vivo of hip-cups made of ultrahigh molecular weight polyethylene (UHMW-PE), the natural antioxidant α-tocopherol was added to the polymer. The added α-tocopherol may however undergo chemical transformations during manufacturing and sterilization by γ-irradiation of hip-cups which may differ from human metabolism. Therefore, the question of the biocompatibility of the respective transformation products was investigated on test samples, which were prepared under the same conditions as applied for the production and sterilization of hip-cups. Thin plates (25×18×2 mm3) were fabricated out of test samples to investigate the cytotoxic activity according to EN 30993-5. In cytotoxicity testing, proliferation, mitochondrial activity and membrane integrity were not influenced by the material. In contrast, cell adhesion and cell spreading were diminished as shown with hemalum staining. In order to investigate the genotoxicity, the α-tocopherol and its transformation products were extracted from test specimens by n-heptane at 185 °C under nitrogen atmosphere. Then the n-heptane was evaporated in vacuo and the remaining α-tocopherol and its transformation products were dissolved in DMSO. The genotoxicity of this extract was then tested by the Ames-test according to DIN UA 12 (1995), which showed no indication for genotoxic activity.
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References
M. Goldman, R. Gronsky, R. Ranganathan R. and L. Pruitt, Polym. 37 (1996) 2909.
P. Eyerer, Kunststoffe 77 (1987) 617.
F. J. Buchanan, B. Sim and S. Downes, Plast., Rub. and Comp. Proc. and Appl. 27 (1998) 148.
E. Brach Del Preyer, M. Crova, L. Costa, A. Dallera, G. Camino and P. Gallinaro, Biomaterials 17 (1996) 873.
L. Costa, M. P. Luda, L. Trossarelli, E. M. Brach Del Prever, M. Crova and P. Galunaro, ibid. 19 (1998) 659.
L. Costa, M. P. Luda, L. Trossarelli, E. M. Brach Del Prever, M. Crova and P. Gallinaro, ibid. 19 (1998) 1371.
M. Goldman, M. Lee, R. Gronsky and L. Pruitt, J. Biomed. Mat. Res. 37 (1997) 43.
B. Dolezel and L. Adamirova, CS patent 221 403 (1981).
B. Frei, K. Briviba and H. Sies in “Natural Antioxidants in Human Health and Disease” (Academic Press, San Diego, 1994) p. 107.
C. Wolf, T. Krivec, J. Blassnig, K. Lederer and W. Schneider, J. Mat. Sci.: Mat in Med., in print.
S. Al-Malaika, C. Goodwin, S. Issenhuth and D. Burdick, Polym. Deg. Stab. 64 (1999) 145.
C. Wolf in “Tests of Biocompatibility of α-Tocopherol for the Use as a Stabilizer in Ultra-High Molecular Weight Polyethylene Cups of Hipendoprostheses” (Diploma thesis, University of Leoben, department for Chemistry of Polymeric Materials, Leoben, 2000).
S. Laermer in “Proceedings of the ADDCON 95, Worldwide Additive and Polymer Conference”, Basel, April 1995.
R. Casani in “Kirk-Othmer, Encyclopedia of Chemical Technology Vol. 25, IV Edition” (John Wiley & Sons, New York, (1997) p. 256.
S. Al-Malaika, H. Ashley and S. Issenhuth, J. Polym. Sci. Part A: Polym. Chem. 32 (1994) 3099.
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Wolf, C., Lederer, K. & Müller, U. Tests of biocompatibility of α-tocopherol with respect to the use as a stabilizer in ultrahigh molecular weight polyethylene for articulating surfaces in joint endoprostheses. Journal of Materials Science: Materials in Medicine 13, 701–705 (2002). https://doi.org/10.1023/A:1015750112343
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DOI: https://doi.org/10.1023/A:1015750112343