*2.5. [111. In]In-IP-001 Cellular Uptake*

To study [111In]In-IP-001 uptake, A549 cells were incubated with 2 MBq of the radiotracer for different times of up to 24 h. Experiments were performed to gain some insights about the kinetics of the accumulation of the radiolabeled compound in vitro, with the aim to design a further and more exhaustive study in vivo. The maximal accumulation was

achieved after 4 h of incubation and was around 5% (expressed as percent of the added radioactivity per million cells). After 8 h, the uptake was only slightly decreased, but it was more than halved after 24 h of incubation. Data elucidated slow kinetics regarding both the uptake and efflux of the radiotracer in vitro. The obtained results are summarized in Figure 2.

**Figure 2.** Uptake of [111In]In-IP-001 by A549 cells at different incubation times (*<sup>n</sup>* = 3; mean <sup>±</sup> SD).
