1. Cell Therapy Center, Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, and Key Laboratory of Neurodegeneration, Ministry of Education, Beijing, China;
2. Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China;
3. Center of Parkinson's Disease, Beijing Institute for Brain Disorders, Beijing, China;
4. Department of Neurobiology, Capital Medical University, Beijing, China;
5. School of Materials Science and Engineering, Tsinghua University, Beijing, China;
6. Institute for Regenerative Medicine and Biomimetic Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing, China