Abstract:

Objective To investigate the effect of a laser-etched pure titanium surface on proliferation of the human osteosarcoma cell line MG63 and to provide a basis for study of implant surface modification. Methods The pure titanium plate was cut into titanium pieces by a numerical control machine tool and divided into smooth surface and laser etching groups. The titanium surface of the laser etching group was etched with an Nd:YAG continuous wave laser using predetermined parameters, and the surfaces were observed by scanning electron microscopy (SEM). The surface micromorphology of each titanium sheet was evaluated. The relative element content of the titanium surface was measured by energy dispersive X-ray spectroscopy (EDS). The Ra value of each surface was determined using the Veeco roughness tester. MG63 cells were inoculated on 2 sets of titanium tablets. At 1, 3, and 6 h postinoculation, cell adhesion to the two groups of titanium sheets was observed under the microscope. At 24 h after inoculation, cellular F-actin was directly stained using immunofluorescence, and the morphology of the cytoskeleton was observed by laser confocal microscopy. Cell proliferation was examined at 1, 3, and 5 d using a MTS kit, and the data were analyzed with SAS 9.4. Results The surface of the smooth surface group was smooth and flat, the element composition was pure titanium, and the roughness Ra was 179.23 nm. The surface of the laser-etched group formed a regular and uniform pore structure. The composition was mainly Ti, O, C, etc, and the surface roughness Ra was 14.11 μm. A large number of cells were uniformly distributed on the two titanium sheets in the observations at 1, 3, and 6 h. At 24 h postinoculation, MG63 cells were completely stretched on the two sets of titanium sheets and had extended a large number of pseudopods and microfilaments to cross-link with peripheral cells; moreover, the cell division phase was observed. The cell proliferation of the two groups at 1, 3, and 5 d showed a significant increase with time, indicating that no cytotoxicity occurred on the surfaces of the two groups. However, the cell proliferation in the laser-etched group was superior to that in the mechanical smooth surface group. Conclusion The surface morphology of titanium can be controlled by laser etching, which is conductive to increase the microstructure of implants without cytotoxicity and promoting osteoblast proliferation in the early stage.

Key words: laser etching, pure titanium, surface treatment, roughness, MG63, proliferation

摘要：

目的 探讨激光蚀刻的纯钛表面对人成骨肉瘤细胞MG63增殖的影响,为种植体表面改性提供研究基础。方法 将纯钛板通过数控机床切割成钛片,分光滑表面组和激光蚀刻组,激光蚀刻组的表面采用Nd:YAG连续波激光,在预定参数下蚀刻钛表面,扫描电子显微镜（scanning electron microscopy,SEM）观察各组钛片表面微形貌,X射线能谱仪（energy dispersive X-ray spectroscopy,EDS）检测钛片表面相对元素含量,使用Veeco粗糙度检测仪检测各组表面的Ra值。将MG63细胞接种于2组钛片上,接种后1 h、3 h、6 h,显微镜下观察2组钛片上细胞粘附情况。接种后24 h,采用细胞肌动蛋白F-actin直接免疫荧光染色,激光共聚焦显微镜观察细胞骨架形态。采用MTS试剂盒检测1 d、3 d、5 d细胞的增殖情况,获得数据采用SAS 9.4进行分析。结果 光滑表面组表面光滑平整,元素组成为纯钛,粗糙度Ra为179.23 nm,激光蚀刻组表面形成规则、大小较均匀的孔洞结构,成分主要由Ti、O、C等,表面粗糙度Ra为14.11 μm。1 h、3 h、6 h观察2组钛片都可见大量细胞均匀粘附。接种后24 h,MG63细胞在2组钛片上已经完全伸展且伸出大量伪足和微丝状结构与周边细胞发生交联,可以观察到细胞分裂相。2组1 d、3 d、5 d的细胞增殖,随时间呈显著的增加趋势,说明2组表面均无细胞毒性,但激光蚀刻组细胞增殖优于光滑表面组。结论 钛表面经过激光蚀刻处理后,表面形貌可控,有利于增加钛表面的微结构,无细胞毒性,能促进MG63细胞的早期增殖。

关键词: 激光蚀刻, 纯钛, 表面处理, 粗糙度, MG63, 增殖