Technetium-99m-labeled genistein as a potential radical scavenging agent

Iodine-131 labeled genistein as a potential radiotracer for breast cancer

Objective

Genistein is an isoflavone compound that has been proven to have anticancer activity and is capable of binding to estrogen β receptors with Selective Estrogen Receptor Modulators (SERMs) properties, and has a strong affinity to inhibit the development of cancer cells. This study is to determine the optimum conditions of the reaction in the synthesis process of compounds labeled ¹³¹I-genestein which can be potential for application of breast cancer diagnosis.

Methods

Synthesis of ¹³¹I-Genistein compound labeling using the Chloramine-T iodination method. This method uses several parameter optimizations, including: pH conditions, the amount of chloramine-T oxidizer and sodium metabisulfite reducing agent. The radiochemical purity of the ¹³¹I-Genistein compound was determined using thin layer chromatography TLC-SG F₂₅₄, and measured by SCA (Single Channel Analyzer). The radiochemical purity of labeled compounds must fulfill the requirements of the United States of Pharmacopeia.

Results

Optimization of the synthesis conditions of the ¹³¹I-Genistein compound was obtained at pH 8, the amount of chloramine-T 0.225 mg, and the amount of Na-Metabisulfite 0.342 mg, with 30 min reaction time. This optimum condition produces radiochemical purity of 95.02 ± 0.76%.

Conclusion

Products labeled ¹³¹I-Genistein meet radiochemical purity requirements according to USP requirements. The labeled compound is expected to be able to be used to detect breast cancer through a binding mechanism with estrogen receptors β.

Applying Quality by Design Principles in the Development and Preparation of a New Radiopharmaceutical: Technetium-99m-Imatinib Mesylate

The clinical impact and accessibility of ^99mTc tracers for cancer diagnosis would be greatly enhanced by the availability of a new, simple, and easy labeling process and radiopharmaceuticals. In this study, Technetium-99m-imatinib mesylate ([^99mTc]TcIMT) was developed and prepared as a new radiopharmaceutical for breast cancer diagnosis. The effect of critical process parameters on the product quality and stability of [^99mTc]TcIMT was investigated using the quality by design concept of the ICH Q8 (Pharmaceutical Development) guideline. [^99mTc]TcIMT was subjected to in vitro cell binding studies to determine healthy and cancer cell affinity using HaCaT and MCF-7 cells, respectively. The optimal radiolabeling procedure with 1 mg of IMT, 500 μg of stannous chloride, 0.1 mg of ascorbic acid, and ^1mCi ^99mTc radioactivity was obtained for [^99mTc]TcIMT. The pH of the reaction mixture was adjusted to 10 and allowed to react for 15 min at room temperature. The radiochemical purity of [^99mTc]TcIMT was found to be higher than 90% at room temperature up to 6 h. Chromatography analysis revealed >85% [^99mTc]TcIMT complex formation with promising stability in saline, cell medium, and serum up to 6 h. The radiolabeled complex showed a higher cell-binding ratio to MCF-7 cells (88.90% ± 3.12) than HaCaT cells (45.64 ± 4.72) when compared to ^99mTc. Our findings show that the developed preparation method for [^99mTc]TcIMT falls well within the proven acceptable ranges. Applying quality by design (QbD) principles is feasible and worthwhile for the preparation of [^99mTc]TcIMT. In conclusion, radiochemical purity, stability, and in vitro cell binding evaluation of the [^99mTc]TcIMT complex indicate that the agent can be utilized for imaging of breast cancer cells.