Assad M, Lemieux N, Rivard C H, Yahia L H
Centre de Recherche Pédiatrique, Hôpital Ste-Justine, Montréal, QC, Canada.
Biomed Mater Eng. 1999;9(1):1-12.
The genotoxicity level of nickel-titanium (NiTi) was compared to that of its pure constituents, pure nickel (Ni) and pure titanium (Ti) powders, and also to 316L stainless steel (316L SS) as clinical reference material. In order to do so, a dynamic in vitro semiphysiological extraction was performed with all metals using agitation and ISO requirements. Peripheral blood lymphocytes were then cultured in the presence of all material extracts, and their comparative genotoxicity levels were assessed using electron microscopy-in situ end-labeling (EM-ISEL) coupled to immunogold staining. Cellular chromatin exposition to pure Ni and 316L SS demonstrated a significantly stronger gold binding than exposition to NiTi, pure Ti, or the untreated control. In parallel, graphite furnace atomic absorption spectrophotometry (AAS) was also performed on all extraction media. The release of Ni atoms took the following decreasing distribution for the different resulting semiphysiological solutions: pure Ni, 316L SS, NiTi, Ti, and controls. Ti elements were detected after elution of pure titanium only. Both pure titanium and nickel-titanium specimens obtained a relative in vitro biocompatibility. Therefore, this quantitative in vitro study provides optimistic results for the eventual use of nickel-titanium alloys as surgical implant materials.
将镍钛合金（NiTi）的遗传毒性水平与其纯成分、纯镍（Ni）和纯钛（Ti）粉末的遗传毒性水平进行比较，并与作为临床参考材料的316L不锈钢（316L SS）进行比较。为此，使用搅拌和符合ISO要求的方法对所有金属进行动态体外半生理提取。然后将外周血淋巴细胞在所有材料提取物存在的情况下进行培养，并使用与免疫金染色相结合的电子显微镜原位末端标记（EM-ISEL）评估它们的比较遗传毒性水平。细胞染色质暴露于纯镍和316L不锈钢时显示出比暴露于镍钛合金、纯钛或未处理对照时明显更强的金结合。同时，还对所有提取介质进行了石墨炉原子吸收光谱法（AAS）检测。对于不同的半生理溶液，镍原子的释放呈现以下递减分布：纯镍、316L不锈钢、镍钛合金、钛和对照。仅在纯钛洗脱后检测到钛元素。纯钛和镍钛合金标本均获得了相对的体外生物相容性。因此，这项定量体外研究为镍钛合金最终用作外科植入材料提供了乐观的结果。
