Niosomes for nose-to-brain delivery: A non-invasive versatile carrier system for drug delivery in neurodegenerative diseases

Neurodegenerative diseases (NDDs) significantly contribute to morbidity and mortality worldwide. The suboptimal effect of currently used therapeutic approaches administered via oral and parenteral routes for treatment of NDDs is mainly due to poor drug delivery to the brain. The blood-brain barrier (BBB), blood-cerebrospinal fluid (CSF) barrier, and brain-CSF barrier pose significant challenges against drug delivery to the brain. To overcome these obstacles, intranasal (IN) delivery has been proposed as a non-invasive strategy for delivery of therapeutic agents to the brain. Drug transport from the nasal cavity to the brain could be achieved via direct transport route utilizing olfactory and trigeminal neuronal pathways or indirectly through systemic absorption. Stemming from the recent nanomedicine field advances and achievements, novel nano-sized carriers have been developed. Niosomes, an emerging type of nanoparticles (NPs) primarily consisting of self-assembled non-ionic surfactant-based bilayer, showed great potential as a platform for efficient delivery of drug molecules to various sites including the brain. The physiological challenges associated with drug delivery to the brain are thoroughly examined in this review, highlighting the role of niosomes as vehicles for nose-to-brain (N2B) drug delivery. Moreover, the methods of preparation, characterization, and potential applications of niosomes as nanocarriers for drug delivery to the brain for treatment of NDDs are evaluated.