Figure 5.

Improved tumor accumulation of ⁸⁹Zr-labelled SN38 thMBs +T compared with VEGFR2-targeted ⁸⁹Zr-labelled SN38 liposomes alone. (A) Schematic depicting the strategy used for radiolabeling of SN38 liposomes and SN38 thMBs. DSPE was radiolabeled with ⁸⁹Zr and incorporated into the lipid shell of liposomes encapsulating SN38 and used to generate therapeutic MBs. (B) Schematic of the experimental groups used to compare VEGFR2-targeted liposomally encapsulated SN38 (LE-SN38) with SN38 thMB +T (n = number of mice per group). (C) Schematic of the experimental protocol used (n = 5 animals per time point). The mean (± S.D.) starting tumor volume measured by mechanical calipers was 340 mm³ ± 134 mm³. (D) PET image from the thMB +T group at each imaging time point. Signal in the liver, spleen and bladder are arrowed, tumor is circled. (E) The percentage injected dose per gram of tissue (%ID/g tissue) in tumor (F) blood (G) liver and (H) spleen were calculated with mean and SEM shown. Unpaired T-test tumor, ***p = 0.0006 at 1 h, *p = 0.0432 at 24 h and *p = 0.026 at 72 h. Blood ****p < 0.0001 at 1 h, liver *p = 0.0494 at 72 h, spleen *p = 0.0326 at 72 h.