Drugs themselves are too large to pass the blood-brain barrier (BBB), but attached to nanoparticles, drugs could permeate the barrier, due to the small size and shape of nanoparticles. The attachment of drugs to nanoparticles will decrease the dosage of drugs, which will lessen toxicity. Attached to a drug, these metals cross to the Central Nervous System, typically through binding with receptors on the exterior surface of the BBB, and are ejected to the interior through vesicles. The application of these nanoparticles includes aid to patients with Alzheimer’s disease, schizophrenia, and various other forms of neurodegenerative diseases. Metals also play an important role in the brain through the regulation of synaptic plasticity, myelination, and the production of neurotransmitters, acting as cofactors.
Green synthesis refers to the most environmentally-friendly way to produce a nanoparticle, most likely a biological or chemical way. Green synthesis of nanoparticles with plant extracts results in less toxic nanoparticles and improves biocompatibility.