title: Phytochemical-loaded mesoporous silica nanoparticles for nose-to-brain olfactory drug delivery.
abstract: Central nervous system (CNS) drug delivery is often hampered due to the insidious nature of the blood-brain barrier (BBB). Nose-to-brain delivery via olfactory pathways have become a target of attention for drug delivery due to bypassing of the BBB. The antioxidant properties of phytochemicals make them promising as CNS active agents but possess poor water solubility and limited BBB penetration. The primary aim of this study was the development of mesoporous silica nanoparticles (MSNs) loaded with the poorly water-soluble phytochemicals curcumin and chrysin which could be utilised for nose-to-brain delivery. We formulated spherical MSNP using a templating approach resulting in ∼220nm particles with a high surface porosity. Curcumin and chrysin were successfully loaded into MSNP and confirmed through Fourier transformation infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and HPLC approaches with a loading of 11-14% for curcumin and chrysin. Release was pH dependant with curcumin demonstrating increased chemical stability at a lower pH (5.5) with a release of 53.2%±2.2% over 24h and 9.4±0.6% for chrysin. MSNP were demonstrated to be non-toxic to olfactory neuroblastoma cells OBGF400, with chrysin (100μM) demonstrating a decrease in cell viability to 58.2±8.5% and curcumin an IC50of 33±0.18μM. Furthermore confocal microscopy demonstrated nanoparticles of <500nm were able to accumulate within cells with FITC-loaded MSNP showing membrane localised and cytoplasmic accumulation following a 2h incubation. MSNP are useful carriers for poorly soluble phytochemicals and provide a novel vehicle to target and deliver drugs into the CNS and bypass the BBB through olfactory drug delivery.
authors.affiliation: Aston Pharmacy School, Life and Health Sciences, Aston University, Birmingham B4 7ET, United Kingdom.
authors.forename: Shital
authors.initials: S
authors.lastname: Lungare
authors.affiliation: Interface Analysis Centre, School of Physics, University of Bristol, Bristol BS8 1TL, United Kingdom.
authors.forename: Keith
authors.initials: K
authors.lastname: Hallam
authors.affiliation: Aston Pharmacy School, Life and Health Sciences, Aston University, Birmingham B4 7ET, United Kingdom. Electronic address: r.k.s.badhan@aston.ac.uk.
authors.forename: Raj K S
authors.initials: RK
authors.lastname: Badhan
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D001921:Brain / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003474:Curcumin / Q000008:administration & dosage* / Q000737:chemistry; D016503:Drug Delivery Systems; D065546:Drug Liberation; D005419:Flavonoids / Q000008:administration & dosage* / Q000737:chemistry; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D016062:Porosity; D012822:Silicon Dioxide / Q000008:administration & dosage* / Q000737:chemistry; D013552:Swine
chemical_list: D005419:Flavonoids; C043561:chrysin; D012822:Silicon Dioxide; D003474:Curcumin
keywords: Flavonoid; Mesoporous silica nanoparticle; Nose-to-brain; Olfactory; Phytochemical