Intranasal administration of dextran-pramlintide polyelectrolyte complex-coated nanoemulsions improves cognitive impairments in a mouse model of Alzheimer's disease

Nasal delivery has emerged as a non-invasive route to administer drugs for brain delivery. In particular, poly- electrolyte complexes-based nanocarriers have been demonstrated to be advantageous for nasal delivery of peptide drugs and vaccines. Pramlintide (Pram) is a peptide that emerges as a novel neuroprotective strategy to modify the pathogenesis of Alzheimer's disease (AD). In this study, we examined the effects of the intranasal administration of dextran-pramlintide polyelectrolyte complex-coated nanoemulsions (PEC-NE DexS/Pram ) in an experimental model of AD induced by intracerebroventricular (i.c.v.) infusion of amyloid-beta (A(31-42) 1-42 ) peptide in mice. PEC-NE DexS/Pram displayed droplet size lower than 200 nm and a negatively charged surface. The locomotor activity of the animals was not affected by the i.c.v. A(3 1-42 injection or Pram treatment. On the other hand, the intranasal administration of PEC-NE DexS/Pram at a dose of 100 mu g/day for 14 consecutive days restored the impairment induced by A(3 1-42 injection in the discriminative learning and the short-term spatial reference memory of mice. However, Pram treatment did not alter the A(3 1-42-induced anhedonic behavior, oxidative stress parameters, or the pre-synaptic SNAP-25 and post-synaptic PSD-95 levels in the hippocampus and prefrontal cortex. These findings indicate cognitive-enhancing properties of intranasal Pram administration in an animal model of AD.