Delivery systems for theranostics in neurodegenerative diseases

Neurodegenerative diseases are characterized by progressive nervous system dysfunction, which affects over 90, 000 people every year. Although numerous contrast agents and therapeutic drugs are available for the diagnosis and therapy of neurodegenerative diseases, there are several limitations to their application. Particularly, these contrast agents and drugs are restricted from entering into the brain because of the blood-brain barrier, which represents a major bottleneck to efficacious and safe theranostics of neurodegenerative diseases. Nanoparticles can offer impressive improvement in the theranostics of neurodegenerative diseases, as they can effectively deliver contrast agents and drugs to target sites in the central nervous system. In this review, we describe various delivery systems, including lipid nanoparticles, polymeric nanoparticles, inorganic nanoparticles, and exosomes useful for the theranostics of neurodegenerative diseases. Finally, we outline current challenges and our perspectives on the development of delivery systems for theranostics of neurodegenerative diseases.