Fig. 4

a U87MG cell uptake of the TDN and Apt-TDN (TDN-Gint4.T). The TDN entered U87MG cells directly without transfection agents, and the uptake of Apt-TDN (linked to the aptamer Gint4.T) was significantly increased and competitively inhibited by free Apt (Gint4.T), indicating that the aptamer Gint4.T plays a significant role in cellular targeting. The scale bar represents 50 μm. b Flow cytometry curves show the intracellular uptake of the TDN, Apt-TDN, and Apt-TDN+Apt after incubation for 3 h