Recent progress of drug nanoformulations targeting to brain.

Most of the potential therapeutic agents capable to modulate the pathophysiology or treat the neurological disorders and brain tumors are useless in the current modern and advanced era of neuroscience due to the impeding action of biological barriers. Among various therapeutic strategies applied for translocation of drug delivery across the blood-brain barrier (BBB), nanoformulations set an excellent platform for brain targeting by overcoming the biological and chemical barriers and protecting drug from efflux to promote the optimum therapeutic drug concentration in brain parenchyma tissues. Nanocarriers are the most widely studied delivery vehicles for BBB translocation with the efficiency of selectively targeting or exploiting inherent biological molecules, receptors, carriers or mechanisms of the brain. Nearly all of the available drug delivery nanocarriers explored in recent years for brain therapeutics and theranostics are based on lipid or polymeric materials. Polymeric nanoparticles (NPs) and lipid based nanocarriers including liposomes, solid lipid NPs (SLNs) and micelles, etc. are under the direct focus of neuroscientists due to the promising attributes and vast applications in neurological disorders. Surface modification of nanovehicles with proper targeting moiety or coating with surfactants promotes the interaction with endothelial cells and passage of nanocarriers to the brain. This review comprehensively depicts challenges to the brain targeted drug delivery, mechanisms of drug transportation across the BBB, and potential contributions of endogenous cells as NPs delivery cells and novel targeting ligands decorated nanoformulations in imaging, treating and controlling neurological disorders.