1. School of Materials Science and Engineering, South China University of Technology, Guangzhou510641, P. R. China
2. National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou510006, P. R. China
3. School of Stomatology, Jinan University, Guangzhou510632, P. R. China
4. Key Laboratory of Biomedical Engineering of Guangdong Province, South China University of Technology, Guangzhou510006, P. R. China