1. School of Material Science and Engineering; Tianjin University; Tianjin 300072 China
2. Department of Chemical and Biomolecular Engineering; University of California; Los Angeles California 90095 USA
3. Department of Neurosurgery; Tianjin Medical University General Hospital; Laboratory of Neuro-Oncology; Tianjin Neurological Institute; Tianjin 300052 China
4. Key Laboratory of Neurotrauma, Variation, and Regeneration; Ministry of Education and Tianjin Municipal Government; Tianjin 300052 China
5. Department of Microbiology; Immunology and Molecular Genetics; University of California; Los Angeles California 90095 USA
6. Tianjin Research Center of Basic Medical Science; Tianjin Medical University; Tianjin 300070 China