预钙化加速类骨磷灰石在镍钛合金表面生长的电化学阻抗谱(英文)

ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY OF ACCELERATED BONE-LIKE APATITE GROWTH ON NICKEL AND TITANIUM ALLOY BY PRE-CALCIFICATION

通过酸碱处理活化NiTi合金表面,在模拟体液中仿生生长类骨磷灰石层以改善其生物相容性。采用电化学阻抗谱研究了预钙化对加速磷灰石沉积的影响,并基于双层模型建立了电子等效电路。结果表明:随着在模拟体液中浸泡时间的延长,化学处理的NiTi合金表面类骨磷灰石不断生长,并且添加预钙化试样浸泡3 d,即可在合金表面生长出均匀完整的类骨磷灰石层,而未预钙化试样表面沉积物稀少。对应电子等效电路中,预钙化试样电阻值明显大于未预钙化试样的,显示预钙化促进了活化NiTi合金表面类骨磷灰石的生长。

In order to improve its biocompatibility, a biomimetic process that treats the NiTi alloy with acid and alkali separately, and then in a simulated body fluid （SBF） was employed to deposit a bone-like apatite coating on a NiTi surface. Effect ofpre-calcification on accelerated apatite growth on the bioactive NiTi in the SBF was investigated using an electrochemical impedance spectroscopy （EIS）. The electrical equivalent circuit based on a two-layer model was proposed. The results show that bone-like apatite is continuously formed on chemically treated NiTi with increasing of immersion time in the SBF. After immersion in the SBF for 3 d, the surface of chemically treated NiTi with pre-calcification is covered with a high density of compact and uniform granules of bone-like apatite, while imperfect coating is observed on the sample surface without pre-calcification. The resistance of the apatite layer on the sample with pre-calcification is obviously higher than the one of the sample without pre-calcification, which indicates the bone-like apatite on chemically treated NiTi is promoted by the pre-calcification process.