In Vitro Characterization Data of 68Ga-Labeled Surrogate Compounds (n = 3)
| Compound | Specific internalization (%AA/105 cells)* | Ki (nM)† | Lipophilicity‡ | Plasma protein binding (%) | |
|---|---|---|---|---|---|
| Mouse | Human | ||||
| PSMA-617 | 0.14 ± 0.04 | 17.8 ± 5.9 | −3.5 ± 0.1 | 63.3 ± 2.4 | 76.7 ± 3.2 |
| PSGa-2 | 0.15 ± 0.06 | 27.4 ± 3.0 | −3.4 ± 0.1 | 66.6 ± 0.5 | 76.4 ± 0.9 |
| PSGa-3 | 0.16 ± 0.03 | 28.7 ± 4.4 | −3.8 ± 0.1 | 55.8 ± 2.3 | 67.5 ± 4.2 |
| PSGa-4 | 0.05 ± 0.01 | 14.7 ± 4.6 | −3.7 ± 0.2 | 55.9 ± 0.9 | 70.5 ± 3.5 |
| PSGa-5 | 0.14 ± 0.05 | 12.9 ± 1.8 | −3.6 ± 0.1 | 66.2 ± 4.7 | 71.8 ± 1.1 |
| PSGa-6 | 0.02 ± 0.01 | 14.1 ± 3.8 | −2.5 ± 0.2 | 51.5 ± 1.5 | 65.6 ± 3.2 |
| PSGa-7 | 0.16 ± 0.02 | 30.5 ± 8.9 | −2.1 ± 0.1 | 83.7 ± 1.0 | 87.3 ± 0.8 |
| PSGa-8 | 0.15 ± 0.03 | 17.7 ± 2.2 | −3.0 ± 0.2 | 81.5 ± 1.2 | 96.7 ± 1.8 |
| PSGa-9 | 0.13 ± 0.04 | 23.4 ± 3.7 | −2.9 ± 0.1 | 84.2 ± 1.1 | 94.0 ± 1.0 |
↵* Specific internalization refers to total internalization (n = 3) corrected with blocked internalization in presence of 500 µM 2-phosphonomethyl pentanedioic acid, expressed as percentage applied activity (%AA) per 105 cells.
↵† Inhibitor constant (Ki) is determined through Cheng–Prusoff method in competition assay (n = 3) with 0.75 nM [68Ga]Ga-PSMA-10 (Kd = 3.8 ± 1.8 nM).
↵‡ Lipophilicity is logDoct/PBS.
oct = n-octanol; PBS = phosphate-buffered saline.