Nanoparticle (NP) translocation from nose versus lungs to brain is differentiated.
Differential exposure of 20 nm radio-NP:nose-only versus intratracheal inhalation
The nose-brain path precedes via nerves, the lungs-brain path via circulation.
NP uptake in the rat brain is nine-fold higher from nose than from lungs.
Relative to deposited NP in both regions it is 45-fold higher than from the nose.