Tracedrawer version 1

The cell-associated uptake of ¹²⁵I-VIP116 when loaded on EGFR-targeted or non-targeting lipodisks was measured using LigandTracer grey (Ridgeview Instruments) at room temperature. Moreover, the uptake of ¹²⁵I-EGF was studied as a reference.
2−3 × 10⁵ HCT-EGFR cells were seeded in a tilted petri dish and incubated for 24–48 h before mounting in the Ligandtracer. A baseline was collected before stepwise adding ¹²⁵I-VIP116-loaded lipodisks to a final total lipid concentration of 2.7, 8 and 24 µM (corresponding EGF concentrations in targeting lipodisks were approximately 3, 9 and 27 nM). The specific activity of ¹²⁵I-VIP116 was 0.5 MBq/nmol in all LigandTracer experiments. For ¹²⁵I-EGF, ligand with concentrations of 1, 3 and 10 nM was used. The background signal was subtracted by measuring the signal on an area with no cells on the same petri dish. Analysis was performed using TraceDrawer version 1.7 (Ridgeview Instruments).

All LigandTracer experiments were performed on LigandTracer Yellow (Ridgeview Instruments, Vänge, Sweden). Approximately 5 × 10⁵ HCT116 or UM-SCC-74B cells were seeded on tilted petridishes 24 h prior to the start of each assay and incubated at 37 °C with 5% CO₂. ¹⁷⁷Lu-AbN44v6 was added in two concentrations (10 and 30 nM), and the uptake was measured at room temperature for 90 min for each concentration followed by a dissociation phase of at least 10 h. Analysis was performed using TraceDrawer version 1.7 (Ridgeview Instruments, Vänge, Sweden).