Effect of graphene-oxide-modified osteon-like concentric microgrooved surface on the osteoclastic differentiation of macrophages.

This study aimed to investigate the effect of new biomimetic micro/nano surfaces on the osteoclastic differentiation of RAW264.7 macrophages by simulating natural osteons for the design of concentric circular structures and modifying graphene oxide (GO).The groups were divided into smooth titanium surface group (SS), concentric microgrooved titanium surface group (CMS), and microgroove modified with GO group (GO-CMS). The physicochemical properties of the material surfaces were studied using scanning electron microscopy (SEM), contact-angle measurement, atomic force microscopy, X-ray photoelectron spectroscopy analysis, and Raman spectroscopy. The effect of the modified material surface on the cell biological behavior of RAW264.7 was investigated by cell-activity assay, SEM, and laser confocal microscopy. The effect on the osteoclastic differentiation of macrophages was investiga-ted by tartrate-resistant acid phosphatase (TRAP) immunofluorescence staining and quantitative real-time polymerase chain reaction (qRT-PCR) experiments.Macrophages were arranged in concentric circles along the microgrooves, and after modification with GO, the oxygen-containing groups on the surface of the material increased and hydrophilicity increased. Osteoclasts in the GO-CMS group were small in size and number and had the lowest TRAP expression. Although it promoted the proliferation of macrophages in the GO-CMS group, the expression of osteoclastic differentiation-related genes was lower than that in the SS group, and the difference was statistically significant (P<0.05).Concentric circular microgrooves restricted the fusion of osteoclasts and the formation of sealing zones. Osteomimetic concentric microgrooves modified with GO inhibited the osteoclastic differentiation of RAW 264.7 macrophages.目的: 本研究通过模拟天然骨单位进行同心圆结构的设计，并修饰氧化石墨烯（GO），探究新的仿生微纳米结构表面对巨噬细胞RAW264.7破骨分化的影响。方法: 实验分为光滑钛片组（SS）、微沟槽组（CMS）和微沟槽表面修饰GO组（GO-CMS），利用扫描电子显微镜（SEM）、接触角测量仪、原子力显微镜、X射线光电子能谱分析仪和拉曼光谱仪研究材料表面的理化性能，通过细胞活性检测、SEM和激光共聚焦显微镜研究修饰后的材料表面对RAW264.7的细胞生物学行为的影响，通过抗酒石酸酸性磷酸酶（TRAP）免疫荧光染色、TRAP定量检测和荧光实时定量聚合酶链反应（qRT-PCR）研究其对巨噬细胞破骨分化的影响。结果: 巨噬细胞沿着微沟槽排列成同心圆状，修饰GO后，材料表面含氧基团增多，亲水性增加。GO-CMS组诱导形成的破骨细胞体积小，数量少，TRAP表达量最少，TRAP单位酶活性也最低。GO-CMS组虽然促进巨噬细胞的增殖，但破骨分化相关基因的表达低于SS组，差异具有统计学意义（P<0.05）。结论: 同心圆微沟槽限制了破骨细胞的融合及封闭区的形成，GO修饰类骨单位同心圆微沟槽抑制了巨噬细胞RAW264.7的破骨分化。.