1. Department of Histology and Embryology School of Basic Medical Sciences Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases The Third Affiliated Hospital of Southern Medical University Southern Medical University Guangzhou 510515 P. R. China
2. Department of Plastic and Aesthetic Surgery Nanfang Hospital of Southern Medical University Guangzhou 510515 P. R. China
3. Regenerative Medicine and Tissue Repair Material Research Center Huangpu Institute of Materials Guangzhou 510530 P. R. China