Preparation and evaluation of [¹²⁵I]troxacitabine: L‐nucleoside model of a potential agent for tumor diagnosis and radiotherapy

Abstract

aIn this study, the optimization of troxacitabine labeling with iodine-125 and its biological evaluation were described. Troxacitabine was labeled via direct electrophilic substitution using chloramine-T as oxidizing agent. The optimum amounts of reactants were: 50 lg troxacitabine, 75 lg Chloramine-T and $19 kBq carrier free Na 125 I. The labeled troxacitabine was stable for more than 24 h. Results of the in-vivo evaluation revealed that the new tracer, [ 125 I]troxacitabine, tends to localize in tissues with high proliferation rate with preferential accumulation in cancerous tissues. Imaging should be carried at 3 h postinjection. The in vitro cell growth inhibition assay showed that the effect of [ 125 I]troxacitabine was stronger than the effect of cold troxacitabine, which strongly suggested that its cytotoxicity was mainly due to radiotoxicity rather than chemotherapeutic activity. The binding assay revealed that [125 I]troxacitabine uptake by the Ehrlich and the ARAC8C cells was high and that it bounded well to DNA.

Preparation, characterization and evaluation of 186Re‐idarubicin: a novel agent for diagnosis and treatment of hepatocellular carcinoma

“…The MTT assay is one of the most versatile and popular mean of measuring the cell activity of living cells via mitochondrial dehydrogenase activity . It involves the conversion of the water soluble 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) to an insoluble formazan in metabolically active cells.…”

Simultaneous SPECT imaging of multi-targets to assist in identifying hepatic lesions

“…99m Tc-3P-RGD 2 20 22 and 131 I-NGA 16 34 were prepared and characterized according to literatures with slightly modification. The details were described in the supplementary file .…”

Radiochemistry

“…The former method was used to prepare iodine-123 labelled iodobenzimidazoles, 140 4-[ 131 I] iodophenylacetic acid 141 and 2-[ 125 I] iodo N-[(S)-{(S)-1-methylpiperidin-2-yl}(phenylmethyl]-3-trifluoromethylbenzamide, 142 whilst [ 125 I] iodocitalopram and iodoescitalopram were made 143 by bromine/iodine-125 exchange; the replacement of a tributylstannyl group by iodine-131 was used to prepare labelled colchicine derivatives. 144 Other standard procedures for labelling molecules with radio-iodine are the chloramine-T method, used in the preparation of [ 125 I]iodotroxacitabine, 145 [ 125 I]iodoquercetin 146 and [ 131 I]iodochlorotoxin, 147 the iodogen procedure which was used to label 8-hydroxyquinoline glucuronide 148 with iodine-125 and -131, the lactoperoxidase method facilitated the labelling of [ 125 I]iodoerythropoietin 149 and the use of hydrogen peroxide as an oxidising agent to make [ 131 I] iodobetulinic acid 150 and [ 131 I] iodoatenolol. 151 It seems possible to 'label' nanoparticles and nanorods with radio-iodine.…”