Figure 3.

Nanobody fusion to ABD extends serum half-life and prolongs 11A4-ABD's tumor accumulation. A) In vivo serum pharmacokinetics up to 4 days (mean concentration (µg/mL) ± SD, n = 4) and B) Biodistribution at day 4 post injection (p.i.) of ¹²⁵I radiolabeled R2 (black) and R2-ABD (grey) intravenously administered to BALB/c nude mice. C) Representative images of BT-474 tumor-bearing mice after single dose administration (50 μg/ mouse) of IR labeled probes. Red arrow: kidney and green arrow: tumors. D) Fluorescence intensity at the tumor site over time (mean ± SD); E) Biodistribution (mean %ID /g ± SD; ** p<0.002, Welch's t-test) and F) IHC of resected tumors (Scale bar = 1 mm) 72 h p.i. from mice injected with 11A4-IR (yellow, n = 2 mice, 4 tumors), 11A4-ABD-IR (green, n = 4, 8 tumors) or R2-ABD-IR (grey, n = 4, 8 tumors).