Ozgenc, E.Karpuz, M.Guler, G.Burak, Z.Başpainar, Y.Gundogdu, E.A.2025-08-272025-08-2720250033-8230https://doi.org/10.1515/ract-2025-0043https://hdl.handle.net/11147/18388Targeted radiopharmaceuticals offer promising approaches for cancer diagnosis and therapy. This study developed freeze-dried kit formulations of 177Lu-Imatinib (IMT) and evaluated their potential efficacy through in vitro studies. Four formulations (F1-F4) containing IMT and chelating agents were prepared and characterized via Fourier transform infrared (FTIR), ultraviolet spectrum (UV), and thermogravimetric analysis (TGA) to confirm complex formation. Biocompatibility was assessed in NIH-3T3 cells using the MTT assay. Radiolabeling with 177Lu was optimized by varying pH, incubation time, and reactant ratios. Radiochemical purity and stability were analyzed over 7 days using HPLC. Binding affinity and cytotoxicity were evaluated in MCF-7 and NIH-3T3 cells. Spectroscopic analyses confirm successful complex formation. All formulations exhibited >90% viability in NIH-3T3 cells. Optimal radiolabeling conditions (45mg IMT-chelator, pH 5, 60min incubation) yielded >90% efficiency, with stable radiolabeling for 7 days. The 177Lu-IMT-DOTA (F3) formulation showed significantly higher binding and cytotoxic effects in MCF-7 cells compared to controls. The 177Lu-IMT-DOTA (F3) kit demonstrates high radiolabeling efficiency, stability, and selective in vitro cytotoxicity toward breast cancer cells, supporting its potential as a targeted radiopharmaceutical. © 2025 Walter de Gruyter GmbH, Berlin/Boston 2025.eninfo:eu-repo/semantics/closedAccessBreast CancerChelating AgentsImatinibLu-177Article2-s2.0-10501072529110.1515/ract-2025-0043