1 Center for Reproductive Medicine, Key Laboratory for Major Obstetric Diseases of Guangdong Province, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, PR China.
2 National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, Guangdong, PR China.
3 Beijing Chao-Yang Hospital Capital Medical University, Beijing, PR, China.