Dendrimers in the context of targeting central nervous system disorders

The treatment of central nervous system disorders, such as Alzheimer's, Parkinson's, traumatic brain injury, brain cancer, etc. is challenging due to the stringent blood-brain barrier (BBB) that restricts the entry of drugs or therapeutic agents. Few invasive strategies, such as reversible disruption of BBB or direct delivery of drug-loaded nanocarriers are effective but suffer from a lack of patient compliance and other drawbacks. Among the non-invasive strategies of systemic delivery of drugs crossing the BBB, dendrimers have gained the significant interest of researchers. Dendrimers are branched three-dimensional polymeric nanostructures with a large number of functional groups that can be modified for tailored-made functionality. The versatility, biocompatibility, capacity to load drugs into the core and surface, and nanosize are the notable advantages of dendrimers. Ligand conjugated dendrimers can cross the BBB and enhance the internalization of the drugs in the target tissues of the brain. A handful of research has established the effectiveness of dendrimers, alone or drug-loaded in several CNS disorders. However, their entry into the clinical trial phase is still restricted. The original review analyzes the favorable outcome of the brain-targeted dendrimer-based research and the associated challenges to their clinical success.