INNOVATIVE NANOCARRIER FOR BRAIN DRUG DELIVERY: MECHANISTIC INSIGHTS AND TRANSLATIONAL CHALLENGES

The Blood brain barrier is a selective protective barrier that nearly all macromolecular therapies and more than ninety eight percent of small molecules cannot cross. The structure is maintained by the neurovascular unit, which is composed of endothelial cells, pericytes, and astrocytes joined by tight junctions that restrict paracellular transit. To address this issue, nanocarriers have demonstrated promise as efficient delivery systems for medications that target the brain. Liposomes, exosomes, polymeric nanoparticles, dendrimers, and biomimetic nanoparticles are the five primary categories of nanocarriers. Passive diffusion, carrier-mediated transport, receptor-mediated transcytosis, and adsorptive-mediated transcytosis are some of the methods by which these carriers can move through the blood-brain barrier. In actuality, they can be used to treat neurological disorders including Parkinson's and Alzheimer's disease, strokes, brain tumours, and traumatic brain injury. Their effectiveness is mostly determined by their size, charge, shape, and surface modifications with specific ligands such as transferrin or polyethylene glycol. However, there are still problems with immunological clearance, instability, low penetration efficiency, and potential neurotoxicity. Future research will focus on improving nanocarrier design, increasing targeting specificity, and addressing regulatory issues in order to implement these innovative brain-targeted therapies.