METHOD: Kind of therapeutics like low molecular weight drugs can be delivered to the CNS via this route. In this review, we have outlined the anatomy and physiological aspect of nasal mucosa, certain hurdles, various strategies including importance of muco-adhesive polymers to increase the drug delivery and possible clinical prospects that partly contribute in intranasal drug delivery.
RESULTS: Exhaustive literature survey related to intranasal drug delivery system revealed the new strategy that circumvents the BBB, based on non-invasive concept for treating various CNS disorders. Numerous advantages like prompt effects, self-medication through wide-ranging devices, and the frequent as well protracted dosing are associated with this novel route.
CONCLUSION: Recently few reports have proven that nasal to brain drug delivery system bypasses the BBB. This novel route is associated with targeting efficiency and less exposure of therapeutic substances to non-target site. Nevertheless, this route desires much more research into the safe transferring of therapeutics to the brain. Role of muco-adhesive polymer and surface modification with specific ligands are area of interest of researcher to explore more about this.
METHODS: We tested the ability of BA at neutral and acidic pH in inducing phosphatidylserine (PS) externalisation, reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP) disruption, and caspase 3/7 activity in normal nasopharyngeal epithelial (NP69) and NPC (TWO4) cells. Inverse-PCR (IPCR) was employed to detect AF9 gene cleavages. To investigate the role of CAD in mediating these cleavages, caspase inhibition was performed. IPCR bands representing AF9 cleaved fragments were sequenced.
RESULTS: BA-treated cells showed higher levels of PS externalisation, ROS production, MMP loss and caspase 3/7 activity than untreated control cells. The effect of BA in the induction of these intracellular events was enhanced by acid. BA at neutral and acidic pH also induced significant cleavage of the AF9 gene. These BA-induced gene cleavages were inhibited by Z-DEVD-FMK, a caspase-3 inhibitor. Intriguingly, a few chromosome breaks were identified within the AF9 region that was previously reported to participate in reciprocal translocation between the mixed lineage leukaemia (MLL) and AF9 genes in an acute lymphoblastic leukaemia (ALL) patient.
CONCLUSIONS: These findings suggest a role for BA-induced apoptosis in mediating chromosome rearrangements in NPC. In addition, CAD may be a key player in chromosome cleavages mediated by BA-induced apoptosis. Persistent exposure of sinonasal tract to gastric duodenal refluxate may increase genomic instability in surviving cells.