RAW264.7细胞来自第三军医大学（中国重庆），在5%二氧化碳下以37℃补充10%FBS的DMEM培养基培养。为了停止细胞增殖，将3×104细胞/cm²的RAW264.7细胞播种不同的基底上培养三天。去除原培养基后加入FDA（2μL、10μg/mL）和DMEM培养基（1mL）的混合液，静置5min。通过激光共聚焦扫描显微镜（德国徕卡市CLSM、TCSSP5）观察染色细胞。

在5%二氧化碳大气下，在37℃下用DMEM培养基补充10%FBS培养分离的成骨细胞。第三代的成骨细胞的初始播种密度为1×104细胞/cm²。对于增殖检测，样品分为两组：预浸泡（0d）和预浸泡（3d）。在预浸泡（0d）组中，在各种基底上直接培养成骨细胞；但在预浸泡（3d）组中，则在培养成骨细胞前将样品在PBS溶液（pH7.4）浸泡3天。在3天培养后，分别通过FDA染色和MTT法研究了成骨细胞在正常或预浸基底上的增殖和可行性。

对CLSM的观察结果如图5A所示，RAW264.7细胞在AT组中明显降低，并在MOF74涂层基底上进一步降低。还发现，AT-MOF74细胞与AT-Mg/Zn2、AT-Mg/Zn3和AT-Mg/Zn4(特别是AT-Mg/Zn3)与RAW264.7细胞具有较高的细胞相容性。

成骨细胞在不同基底培养3天后，在Ti和AT表面观察到许多细胞，而很少有细胞粘附在MOF74修饰基底上(图5A)。然而，一旦样品在PBS溶液中预先浸泡3d，由于MOF74涂层的充分降解，除了AT-Mg/Zn5外，所有经MOF74修饰的样品都没有表现出明显的细胞毒性。与其他预浸泡的底物相比，AT-Mg/Zn5对成骨细胞仍然表现出一定的细胞毒性。

RAW264.7 cells were obtained from the Third Military Medicine University (Chongqing, China) and cultured with DMEM medium supplemented with 10% FBS at 37 °C under 5% CO₂ atmosphere. For as sessment of cellular proliferation, RAW264.7 cells at 3 × 104 cells/cm² were seeded onto different substrates for 3 d. Mixture solution of FDA (2 μL, 10 μg/mL) and DMEM medium (1 mL) was added to each well for 5 min after removing the original medium. The stained cells were visualized via confocal laser scanning microscope (CLSM, TCS SP5, Leica, Germany).

The isolated osteoblasts were cultured with DMEM medium supplemented with 10% FBS at 37 °C under 5% CO₂ atmosphere. Osteoblasts at the third passage were employed in following cellular assays at an initial seeding density of 1 × 104 cells/cm².For proliferation detection, samples were divided into two groups: presoak (0 d) and presoak (3 d). In the group of presoak (0 d), osteoblasts were directly cultured on various substrates; but in presoak (3 d)group, samples were soaked into PBS solution (pH 7.4) for 3 d before osteoblasts culture. After 3 d of culture, the proliferation and viability of osteoblasts on normal or presoaked substrates were investigated via FDA staining and MTT assay, respectively.

As shown in CLSM observation from Fig. 5A, RAW264.7 cells obviously decreased in AT group and further reduced on MOF74-coated substrates. It was also found that AT-Mg/Zn2, AT-Mg/Zn3 and AT-Mg/ Zn4 (especially AT-Mg/Zn3) had the relatively higher cytocompatibility to RAW264.7 cells than other three MOF74 samples.

After culturing osteoblasts onto different substrates for 3d, many cells were observed on Ti and AT surfaces while few cells adhered on MOF74-modifified substrates (Fig. 5A). However, once samples were presoaked for 3 d in PBS solution, all MOF74-modifified samples did not show obvious cytotoxicity except AT-Mg/Zn5 due to the sufficient degradation of MOF74 coatings. Compared with other presoaked substrates, AT-Mg/Zn5 still showed some cytotoxicity to osteoblasts.