Effect of apatite micropattern coating on bone formation

作为初步实验，考察了羟基磷灰石涂层对成骨细胞活性的影响。将成骨样细胞(MC3T3-E1)接种于含或不含仿生羟基磷灰石涂层的聚醚砜平板上。有涂层的平板上的细胞产生更多的蛋白质，这表明比没有涂层的平板上的细胞有更多的增殖。相反，未包被的平板上的细胞显示出更多的碱性磷酸酶活性，表明分化程度更高。接下来，将细胞培养在三种微图案涂层的平板上，即平行线图案(50和100μm)和点图案。然而，在初步实验中，与全涂层或非涂层平板相比，这些平板并没有促进细胞增殖或分化。因此，我们试图制作微小的微图案，以改变成骨细胞的活性。然而，由于涂层磷灰石的脱落，很难制作出统一的、可重复的图案。人们尝试了四种不同的包衣方法，但均未成功。最近，人们发现，通过精确控制模拟体液的浓度、pH和温度，可以成功地制作出均匀的微图案。

As a preliminary experiment, the effect of hydroxyapatite coating on osteoblasts activity was examined. Osteoblast-like cells (MC3T3-E1) were cultured on polyethersulfone plates with or without biomimetic hydroxyapatite coating. The cells on the coated plates produced more proteins, suggesting more proliferation than the cells on the non-coated plates. On the contrary, the cells on the non-coated plates showed more alkaliphosphatase activity, suggesting more differentiation. Next, the cells were cultured on three kinds of plates with micropattern coating, that is, parallel line pattern (50 and 100 μm) and dot pattern. However, these plates did not accelerate cell proliferation nor differentiation compared with total-coated or non-coated plates in the preliminary experiments. Therefore we tried to make minuter micropattens, which may change the osteoblast activity. However, it was difficult to make a unifirm, reproducible pattern due to detachment of the coated apatite. Four different coating methods were tried without success. Recently, it was found that uniform micropattern was successfully made by precise control of concentration, pH, and temperature of the simulated body fluid solution.