FIG 1.

Intranasal (IN) administration delivers liposomes to mouse lungs better than intramuscular (IM) administration, where liposome-displayed HA is uptaken by resident immune cells. (A) Fluorescent imaging of tissues excised from mice treated with fluorescent PoP/PHAD liposomes. (B) PoP fluorescence in immune cells assessed by flow cytometric analysis of lung cell suspensions following enzymatic digestion. HA with fluorescent-labeled DY490 bound to CoPoP/PHAD liposomes show uptake into immune cells extracted from lung homogenates observed with flow cytometry. (C to E) Fluorescence at 490 nm in B cells (C), macrophages (D), and dendritic cells (E) indicates uptake of the H3 antigen. CoPoP image in panel A representative of organ samples from animals analyzed in panel B. Statistical analysis was performed in panel B by two-way ANOVA with Tukey’s multiple-comparison test and in panels C to E by one-way ANOVA with Tukey’s multiple-comparison test. *, P < 0.05; **, P < 0.01; ***, P < 0.005; and ****, P < 0.001. n = 4 mice per group.