FIG. 7.

Internalization of bifunctional aptamer-DOX conjugates with an in vitro BBB model. Each bifunctional aptamer-DOX conjugate was incubated in the luminal compartment of the in vitro BBB for 240 min at 37°C before trypsinization of cells in the abluminal compartment (MDA-MB-231 and HEK293T) and visualization using laser scanning confocal microscopy. An anti-EpCAM antibody was used to differentiate EpCAM-positive MDA-MB-231 cells. Data are representative of three independent experiments. Yellow: anti-EpCAM antibody; red: TYE665-labeled TEPP-DOX conjugate; green: DOX; and blue: Bisbenzimide Hoechst (3 μg/mL; Sigma). Scale bar: 10 μM (n = 3). BBB, blood–brain barrier. Color images are available online.