The aim of this study was to assess the radiosensitivity of bismuth sulfide nanoparticles conjugated with a synthetic agonist analog of gonadotropin-releasing hormones in targeted radiotherapy for breast cancer. After synthesis and characterization of nanoparticles, cytotoxicity of nanoparticles was measured by MTT assay, and the survival fraction was determined by colony formation assay. Finally, flow cytometry was performed to identify the mechanism of radiosensitization. Characterization results determined the spherical shape of Bi₂S₃@BSA with an average size of 8.649 ± 1.6 nm, and Fourier transform infrared confirmed the successful binding of triptorelin to the surface of the nanoparticles. MTT test results show that the Bi₂S₃@BSA–triptorelin did not cause any toxicity () even up to 75 μg/ml. At all doses of ionizing radiation, colony formation assays showed that the nontoxic concentration of Bi₂S₃@BSA–triptorelin significantly increased cell death in MCF-7 cells compared to Bi₂S₃@BSA (). The apoptosis test also confirmed colony formation assay results at all doses and introduced apoptosis as a mechanism of radiosensitivity produced by nanoparticles. Certainly, targeted bismuth sulfide nanoparticles can be a good candidate for increasing radiosensitivity against tumor cells.

中文翻译：

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在乳腺癌细胞放射治疗中使用曲普瑞林共轭硫化铋纳米颗粒 (Bi2S3@BSA) 增强放射敏感性

The aim of this study was to assess the radiosensitivity of bismuth sulfide nanoparticles conjugated with a synthetic agonist analog of gonadotropin-releasing hormones in targeted radiotherapy for breast cancer. After synthesis and characterization of nanoparticles, cytotoxicity of nanoparticles was measured by MTT assay, and the survival fraction was determined by colony formation assay. Finally, flow cytometry was performed to identify the mechanism of radiosensitization. Characterization results determined the spherical shape of Bi₂S₃@BSA with an average size of 8.649 ± 1.6 nm, and Fourier transform infrared confirmed the successful binding of triptorelin to the surface of the nanoparticles. MTT test results show that the Bi₂S₃@BSA–曲普瑞林没有引起任何毒性（)甚至高达 75  μ g/ml。_{在所有剂量的电离辐射下，集落形成测定表明，与 Bi 2} S ₃ @BSA，无毒浓度的 Bi ₂ S ₃ @BSA–曲普瑞林显着增加了 MCF-7 细胞的细胞死亡). 细胞凋亡试验还证实了所有剂量的集落形成测定结果，并将细胞凋亡作为纳米粒子产生的放射敏感性机制引入。当然，靶向硫化铋纳米颗粒可以成为增加对肿瘤细胞的放射敏感性的良好候选者。