Imageable Brachytherapy with Chelator‐Free Radiolabeling Hydrogel
Zhencun Cui, Liqin Wang, Wei Liu, Dan Xu, Taofeng Zhang, Baoliang Ma, Kai Zhang, Lingyan Yuan, Zhitong Bing, Jiangyan Liu, Bin Liu, Wangsuo Wu, Longlong Tian
Abstract
Abstract Brachytherapy stands as an essential clinical approach for combating locally advanced tumors. Here, an injectable brachytherapy hydrogel is developed for the treatment of both local and metastatic tumor. Fe‐tannins nanoparticles are efficiently and stably radiolabeled with clinical used therapeutic radionuclides (such as 131 I, 90 Y, 177 Lu, and 225 Ac) without a chelator, and then chemically cross‐linked with 4‐armPEG‐SH to form brachytherapy hydrogel. Upon intratumoral administration, magnetic resonance imaging (MRI) signal from ferric ions embedded within the hydrogel directly correlates with the retention dosage of radionuclides, which can real‐time monitor radionuclides emitting short‐range rays in vivo without penetration limitation during brachytherapy. The hydrogel's design ensures the long‐term tumor retention of therapeutic radionuclides, leading to the effective eradication of local tumor. Furthermore, the radiolabeled hydrogel is integrated with an adjuvant to synergize with immune checkpoint blocking therapy, thereby activating potent anti‐tumor immune responses and inhibiting metastatic tumor growth. Therefore, this work presents an imageable brachytherapy hydrogel for real‐time monitoring therapeutic process, and expands the indications of brachytherapy from treatment of localized tumors to metastatic tumors.