**4. Conclusions**

This study evaluates the effects of Al template with various structures on cell cultures. The results can be used for the reference on bone or dental implants. The Al template with the flat-structure was slightly hydrophilic; the Al template with micro-structure formed by micro-powder blasting was more hydrophilic. The Al template with nano-structure became superhydrophilic by the anodization method. The Al template with micro/nano-structure became superhydrophilic, and it had the maximum value of contact angle. The Al template with micro/nano-structure had the maximum value of surface roughness, followed by the Al template with micro-structure, followed by the smooth Al template, and the Al template with nano-structure had the minimum value. Osteoblast-like cells (MG63) were

cultured on the variously structured templates for 4 h, 1 day, and 4 days, before the MTT assays were performed. The results revealed that the Al template with micro/nano-structure had the highest OD value. The reason is that this template had the superhydrophilic property and the maximum surface roughness. The Al template with micro/nano-structure was more suitable for cell culture in this study.

**Acknowledgments:** The authors would like to gratefully acknowledge of financial support from National Taipei University of Technology-Taipei Medical University Joint Research Program (NTUT-TMU-101-12).

**Author Contributions:** Ming-Liang Yen and Yung-Kang Shen conceived and design the experiments; Hao-Ming Hsiao and Chiung-Fang Huang performed the experiments; Yi Lin, Yu-Liang Tsai and Chun-Wei Chang analyzed the data; Hsiu-Ju Yen, Yi-Jung Lu and Yun-Wen Kuo contributed analysis tools; Ming-Liang Yen and Yung-Kang Shen wrote the paper.

**Conflicts of Interest:** The authors declare no conflict of interest.
