1. Department of Bioengineering University of Pennsylvania 210 S. 33rd Street, 240 Skirkanich Hall Philadelphia PA 19104 USA
2. Center for Neuroengineering & Therapeutics University of Pennsylvania 240 S. 33rd Street, 301 Hayden Hall Philadelphia PA 19104 USA
3. Center for Neurotrauma, Neurodegeneration, and Restoration Corporal Michael J. Crescenz Veterans Affairs Medical Center 3900 Woodlawn Ave. Philadelphia PA 19104 USA
4. Department of Chemistry Georgetown University 37th & O Streets NW Washington, DC 20057 USA
5. Department of Neurosurgery University of Pennsylvania 3400 Spruce Street Philadelphia PA 19104 USA
6. Department of Physical Medicine & Rehabilitation University of Pennsylvania 1800 Lombard Street Philadelphia PA 19147 USA
7. Department of Materials Science and Engineering A. J. Drexel Nanomaterials Institute Drexel University Philadelphia PA 19104 USA
8. Department of Neurology University of Pennsylvania 3400 Spruce Street Philadelphia PA 19104 USA