1. Introduction2. Barriers for Brain Drug Delivery3. Physiology of the Blood–Brain Barrier4. Invasive Drug Delivery Approaches5. Noninvasive Drug Delivery Approaches6. Nanotechnology Approaches7. Active Blood–Brain Barrier Targeting Strategies8. Novel Nanoplatforms and Delivery Vehicles for BBB Targeting9. Development of Neurodiagnostic Nanoimaging Platforms10. Conclusion