Ghosh Sanchita, Banerjee Debashis, Guleria Apurav, Chakravarty Rubel
Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India; Radiochemistry Division (BARC), Variable Energy Cyclotron Centre, 1/AF, Bidhan Nagar, Kolkata 700064, India.
Nucl Med Biol. 2024 Nov-Dec;138-139:108947. doi: 10.1016/j.nucmedbio.2024.108947. Epub 2024 Aug 23.
Astatine-211 has attained significant interest in the recent times as a promising radioisotope for targeted alpha therapy (TAT) of cancer. In this study, we report the production of At via Bi (α, 2n) At reaction in a cyclotron and development of a facile radiochemical separation procedure to isolate At for formulation of nanoradiopharmaceuticals.
Natural bismuth oxide target in pelletized form wrapped in Al foil was irradiated with 30 MeV α-beam in an AVF cyclotron. The irradiated target was dissolved in 2 M HNO followed by selective precipitation of Bi as Bi(OH) under alkaline condition. The radiochemically separated At was used for labeling cyclic RGD peptide conjugated gold nanoparticles (Au-RGD NPs) by surface adsorption. The radiochemical stability of At-Au-RGD NPs was evaluated in phosphate buffered saline (PBS) and human serum media.
The batch yield of At at the end of irradiation was ∼6 MBq.μA.h. After radiochemical separation, ∼80 % of At could be retrieved with >99.9 % radionuclidic purity. Au-RGD NPs (particle size 8.4±0.8 nm) could be labeled with At with >99 % radiolabeling yield. The radiolabeled nanoparticles retained their integrity in PBS and human serum media over a period of 21 h.
The present strategy simplifies At production in terms of purification and would increase affordable access to this radioisotope for TAT of cancer.
近年来，砹 - 211作为一种有前景的用于癌症靶向α治疗（TAT）的放射性同位素引起了广泛关注。在本研究中，我们报告了通过回旋加速器中铋（α，2n）砹反应生产砹，并开发了一种简便的放射化学分离程序，以分离砹用于制备纳米放射性药物。
将包裹在铝箔中的颗粒状天然氧化铋靶在AVF回旋加速器中用30 MeV的α束辐照。辐照后的靶溶解在2 M HNO中，然后在碱性条件下将铋选择性沉淀为Bi(OH)。通过表面吸附，将放射化学分离得到的砹用于标记环状RGD肽偶联的金纳米颗粒（Au-RGD NPs）。在磷酸盐缓冲盐水（PBS）和人血清介质中评估了At-Au-RGD NPs的放射化学稳定性。
辐照结束时砹的批量产率约为6 MBq·μA·h。放射化学分离后，约80%的砹可以回收，放射性核素纯度>99.9%。Au-RGD NPs（粒径8.4±0.8 nm）可以用砹标记，标记产率>99%。放射性标记的纳米颗粒在PBS和人血清介质中21小时内保持其完整性。
本策略在纯化方面简化了砹的生产，并将增加这种放射性同位素用于癌症TAT的可及性。
