Nanoparticles gained a great interest due to their pharmaceutical and medical effects. These effects relied on its small particle size, surface charge, intensity and bioavailability of nano-sized particles. As the brain is a challenging organ for drug delivery, the nano-biotechnologies in which the nanoparticles are used as a carrier for active ingredients is very important technique that can provide more specific drug targeting and delivery, reduction in toxicity while maintaining therapeutic effects, greater safety and biocompatibility, and faster development of new safe medicines. Different types of nanoparticles are widely used today zinc oxide nanoparticles (ZnONPs), silver nanoparticles (AgNPs), titanium dioxide nanoparticles (TiO2), silica nanoparticles (SiNPs) and gold nanoparticles (AuNPs). The Gold nanoparticles have different types, gold nanoshells, gold nanocages, gold nanosphere (AuNSs) and gold nanorods (AuNRs). Much research has been carried out on the medical applications of gold nanoparticles. The AuNPs now have many pharmaceutical and medical applications because of their investigated and proved antibacterial, Anticancer, Anti-inflammatory and antioxidant activities.