Abstract
Increasing the quantity of brain insulin has been demonstrated to play an important role in various neurological and pathological conditions. Controlling brain insulin levels might thus be important for cognitive functions and food intake. The goal of this study was to test the feasibility of increasing brain insulin levels by intranasal administration of insulin in microemulsion. Application of daily intranasal fluorescently labeled insulin (FITC-insulin) by water-in-oil microemulsion for 5 consecutive days to rats resulted in a significantly higher brain labeling compared with the aqueous solution as measured using quantitative image analysis of brain sections, that is, a two-fold higher average value than the average fluorescence level obtained after the same regimen of intranasal applications by an aqueous solution. Interestingly, the fluorescence level in the brain after nasal applications of an aqueous solution was comparable with the intravenous administration of insulin, which may imply that the transport through the olfactory route after nasal application may compensate the poor systemic absorption of insulin solution by this route. The substantially high brain uptake of insulin, which has been shown following intranasal administration via microemulsion, is of great potential to targeting insulin to the brain in patients with neurological disorders, such as Alzheimer's disease.
Original language | English |
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Journal | Journal of Nanomedicine and Nanotechnology |
Volume | 3 |
Issue number | 4 |
DOIs | |
State | Published - 1 Jun 2012 |
Keywords
- Alzheimer's disease
- Blood-brain barrier
- Brain targeting
- Insulin
- Intranasal drug delivery
- Microemulsion
ASJC Scopus subject areas
- Bioengineering
- Medicine (miscellaneous)
- Biomedical Engineering
- Pharmaceutical Science