Fig. 5.

Retention and activity of UCNP-R-T in the human breast adenocarcinoma SK-BR-3 xenografts on athymic mice. (A) Retention of UCNP-R-Ts in the tumor. A time-lapse series of the overlays of the bright-field and epiluminescence images of a tumor-bearing mouse acquired by a home-built whole-animal imaging system. The excitation/emission in the epiluminescence mode, 980 nm/485–831 nm. The images were captured at specified time intervals, following an intratumoral injection of UCNP-R-T at a dose of 10 μg/g. (Magnification: 2×.) (B) Dynamics of the radioactivity decrease in the tumor following an intratumoral injection of UCNP-R-T at a dose of 10 μg/g. The initial radioactivity was 0.8 MBq. Upper (orange rectangles), middle (green circles), and lower (blue triangles) curves show decrease of the UCNP-R-T radioactivity in the tumor due to ⁹⁰Y decay, UCNP-R-T clearance from the tumor calculated based on UCNP photoluminescence, and combined effects of ⁹⁰Y decay plus UCNP-R-T clearance. (C) Time evolution of the specific radioactivity of UCNP-R-T following an intratumoral injection at doses of 10 μg/g (0.8 MBq) and 15 μg/g (1.2 MBq).