Ducheyne P, Bianco P D, Kim C
Department of Bioengineering, University of Pennsylvania, Philadelphia 19104.
Biomaterials. 1992;13(9):617-24. doi: 10.1016/0142-9612(92)90030-r.
The possible mechanism of minimization of prosthesis-derived bone growth inhibitors by shielding of the metal and the reduction, if not elimination, of the associated metal dissolution was investigated. Titanium, aluminium and vanadium release rates were determined in vitro for Ti alloy specimens both with and without a calcium phosphate coating. Ti orderly oriented wire mesh (OOWM) porous coatings on Ti-6Al-4V substrates were used as the metal specimens. Half of the specimens were coated with a 75 microns calcium phosphate ceramic (CPC coating). Seven reference (OOWM) and seven coated (OOWM-CPC) specimens were immersed and placed along with seven control solutions for various periods in an incubator maintained at 37 degrees C and 5% CO2 - air atmosphere. Whereas the reference solutions showed a Ti release increasing as a function of time, the solutions that had the CPC-coated specimens contained no measurable amounts of titanium. The Al in solution around the CPC-coated specimens was significantly greater than the concentration around non-coated specimens. The Al, however, did not increase significantly with time, at least up to 4 wk immersion. The ceramic coating had a small beneficial effect on V concentration. In the absence of a significant adverse effect of Ti on local bone tissue formation, we focus on the Al data of our study. The possible adverse effect of this element is well documented. The calcium phosphate coating produced a significant increase of biological fixation, yet at the same time a greater Al release into solution, calling into question the significance of CPC coating in shielding adverse metal passive dissolution to explain enhanced bone growth [corrected].
研究了通过金属屏蔽使假体衍生的骨生长抑制剂最小化以及减少（如果不能消除）相关金属溶解的可能机制。测定了有和没有磷酸钙涂层的钛合金试样在体外的钛、铝和钒释放率。使用Ti-6Al-4V基体上的钛有序取向丝网（OOWM）多孔涂层作为金属试样。一半试样涂覆有75微米的磷酸钙陶瓷（CPC涂层）。将七个对照（OOWM）试样和七个涂覆（OOWM-CPC）试样与七种对照溶液一起在保持于37℃和5%二氧化碳-空气气氛的培养箱中浸泡不同时间。对照溶液显示钛释放随时间增加，而含有CPC涂覆试样的溶液中未检测到钛。CPC涂覆试样周围溶液中的铝明显高于未涂覆试样周围的浓度。然而，铝浓度至少在浸泡4周内没有随时间显著增加。陶瓷涂层对钒浓度有轻微的有益影响。在钛对局部骨组织形成没有显著不利影响的情况下，我们关注本研究中的铝数据。该元素可能的不利影响已有充分记录。磷酸钙涂层显著提高了生物固定，但同时有更多的铝释放到溶液中，这使人质疑CPC涂层在屏蔽不利的金属被动溶解以解释骨生长增强方面的意义[已修正]。
