Fig. 9.

Confocal microscopy analysis of frozen section of nasal mice tissue after different time points. Nasal biodistribution of the OVA-TRITC:NPL-FITC in three representative depth of the mice nose are reported, from the anterior segment (I) to the posterior segment (III). Enlargements of the regions in the white frames are reported. Nuclei were stained with Hoechst, NPL are labeled with FITC and OVA with TRITC. Scale bars 50 μm (A–J) and 10 μm (A′–J′). In vivo NPL endocytosis was confirmed and no NPL transcytosis was observed.