2.7.2. Immunohistofluorescence Biodistribution

To study the biodistribution of the DEX carried in the LPNCs, immunohistofluorescence (IHF) experiments were carried out. Permeation and skin slices were carried out in the same way as in Section 2.7.1, but the slices were 10 µm thick. Then, 15 µL of a 1/300 dilution of the rabbit polyclonal primary anti-DEX IgG were added, and the samples were left to incubate in a humid environment overnight at 4 ◦C. Then, the samples were washed with TPBS and incubated with a 1/300 diluted fluorescent secondary goat antirabbit IgG Alexa 488 for 2 h under the same incubation conditions. Finally, ProLong Gold Antifade mounting medium was added. The samples were analyzed under a fluorescent field effect microscope. A L5 Leica filter cube was used, and the filters were BP480/40, BS505 for excitation, and BP 527/30 for emission. To study the possible non-specific interactions of the skin, the same process was carried out with non-treated skin samples and processed in the same way as test samples. The resultant intensity was subtracted from the profiles of the samples using the ImageJ software.
