Nasal lavage fluids and serum collection
At 24 h after the last intranasal administration, mice were sacrificed
by cervical dislocation. PBS (1 ml) was injected into the posterior
nostril and a 1.5-mL EP tube was used to collect the nasal lavage fluid
at the anterior nostril. The nasal lavage fluid was centrifuged at 2000
rpm for 7 min at 4°C and stored at −20°C until analysis. Blood samples
were collected from the orbital venous plexus by capillaries. The blood
samples were rested for 60 min, centrifuged at 4000 rpm for 10 min at
4°C, and stored at −20°C until analysis.