Fig. 3: Internalization study of full-length antibody, fragmented antibody, and fragmented antibody-based bioconjugates.

Normal or high glucose-treated MRGECs and MPC5 cells were treated at 4 °C with Cy5-labeled anti-VEGFR2, anti-VEGFR2 F(ab′)2, and anti-VEGFR2 F(ab′)2-SS31 (red); the three constructs bound at this temperature and were found inside the cells once internalization was allowed by incubating at 37 °C for 1 h. High glucose-treated cells showed a better internalization ability than the normal groups. Nuclei, stained with DAPI, are shown in blue. Scale bars, 50 μm. The experiments were repeated independently for three times with similar results. VEGFR2 vascular endothelial growth factor receptor 2, MRGEC mouse renal glomerular endothelial cells, MPC5 mouse podocytes, DAPI 4′,6-diamidino-2-phenylindole.