Preparation, Quality Control, and Biodistribution Assessment of [111In]In-Dota-Pr81 in Balb/C Mice Bearing Breast Tumors Publisher Pubmed



Abbas Abadi S¹ ; Alirezapour B² ; Kertesz I³ ; Rasaee MJ⁴ ; Mohammadnejad J⁵ ; Paknejad M⁶ ; Yousefnia H² ; Zolghadri S⁷
Source: Journal of Labelled Compounds and Radiopharmaceuticals Published:2021

Abstract

In this study, [111In]In-DOTA-PR81 was developed, and its preliminary preclinical qualifications were assessed for single photon emission computed tomography (SPECT) imaging of breast cancer. DOTA-NHS-ester was practiced and successively purified by molecular filtration. The chelate:mAb ratio was determined by spectrophotometry. DOTA-PR81 was radiolabeled with In-111 and its radiochemical yield, in vitro stability, in vitro internalization, and immunoreactivity tests were performed. SPECT imaging and tissue counting were applied to evaluate the tissue distribution of [111In]In-DOTA-hIgG and [111In]In-DOTA-PR81 in BALB/c mice bearing breast tumors. The radiochemical yield of [111In]In-DOTA-PR81 complex was >95.0 ± 0.5% (ITLC), and the specific activity was 170 ± 44 MBq/mg. Conjugation reaction resulted in the average number of chelators attached to a mAb (c/a) of 3.4 ± 0.3:1. The radioimmunoconjugate showed immunoreactivity towards MCF7 cell line and MUC1 antigen while its significant in vitro and in vivo stability were investigated over 48 h, respectively (93.0 ± 1.2% in phosphate-buffered saline (PBS) and 84.0 ± 1.3% in human serum). The peak concentration of internalized activity of [111In]In-DOTA-PR81 was between 4 to 6 h. In comparison with control probes, the complex was accumulated with high specificity and sensitivity at the tumor site. Achieved results indicated that [111In]In-DOTA-PR81 could be contemplated as an appropriate radiotracer for prognostic imaging of antigens in oncology. © 2020 John Wiley & Sons, Ltd.