含锶锌黄长石涂层钛表面促进骨髓间充质干细胞成骨分化的初步研究

Zinc/strontium-incorporated calcium-silicon coating on titanium and the preliminary evaluation of its osteogenic differentiation on BMMSCs

目的钛合金表面制备新型含锶锌黄长石(Sr-Ca_2ZnSi_2O_7,Sr-HT)涂层,初步评估其对骨髓间充质干细胞(BMMSCs)成骨分化等生物学行为的调控能力,用于指导新型种植体设计以促进骨结合效果。方法采用等离子喷涂法对钛合金表面进行Sr-HT涂层修饰,分别以锌黄长石(Ca_2ZnSi_2O_2,HT)以及羟磷灰石(HAp)涂层钛表面作为对照。扫描电镜观察涂层的表面结构,并使用电感耦合等离子体发射光谱仪(ICP-OES)检测表面涂层的离子释放情况。原代培养犬骨髓间充质干细胞(BMMSCs)并接种于材料表面,用免疫荧光法观察细胞在三种涂层表面的粘附铺展情况,ALP半定量检测和OCN蛋白表达免疫荧光法观察细胞在三种涂层表面的成骨分化情况。结果扫描电镜下观察,三种涂层表面均为凸凹不平的微米尺度结构,与HAp涂层相比,Sr-HT和HT组浸提液中含有锌离子,Sr-HT涂层还能够释放大量锶离子。BMMSCs在Sr-HT和HT涂层表面粘附能力、ALP活性和OCN蛋白表达均显著高于HAp对照组,其中Sr-HT组更明显。结论与传统HAp涂层相比,新型Sr-HT涂层可促进BMMSCs的粘附和成骨分化,其促进成骨分化的作用与Zn和Sr离子释放有关。

Objective To evaluate the behavior of bone marrow mesenchymal stem cells （BMMSCs）on novel Sr- Ca2ZnSi207 （Sr-HT） coating in vitro. Methods The SEM experiment was performed to characterize the morphology of Sr- HT coating. The accumulated ion concentrations of the dissolution products were measured using an inductively coupled plasma/optical emission spectroscopy （ICP-OES）. Ca2ZnSi207 （HT） and hydroxyapatite （Hap） coatings were used as control groups and the adhesion and osteogenic differentiation of BMMSCs on the surfaces of different coating were evaluated and analyzed. Results Sr-HT, HT and HAp coatings had a microscale structure at low magnification and their main difference was ion composition of extracts. Compared to HAp coating, a large number of Zn ions were detected in the extracts of the Sr-HT and HT coatings and plenty of Sr ions were released from Sr-HT coating. The adhesion and osteogenic differentiation of BMMSCs cultured on Sr-HT and HT coatings were significantly higher than that on HAp coating. Besides, Sr-HT coating displayed the best osteogenic differentiation effect on BMMSCs. Conclusions The novel Sr-HT coating has a positive effect on BMMSCs adhesion and osteogenic differentiation as compared with the traditional HAp coating.