Amplification of Tumor Oxidative Stresses with Liposomal Fenton Catalyst and Glutathione Inhibitor for Enhanced Cancer Chemotherapy and Radiotherapy
Ziliang Dong, Liangzhu Feng,* Yu Chao, Yu Hao, Muchao Chen, Fei Gong, Xiao Han, Rui Zhang, Liang Cheng, and Zhuang Liu*
Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, 199 Ren’ai Road, Suzhou 215123, Jiangsu, P.R. China
Amplification of intracellular oxidative stress has been found to be an effective strategy to induce cancer cell death. To this end, we prepare a unique type of ultrasmall gallic acid-ferrous (GA−Fe(II)) nanocomplexes as the catalyst of Fenton reaction to enable persistent conversion of H2O2 to highly cytotoxic hydroxyl radicals (•OH). Then, both GA−Fe(II) and L-buthionine sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, are coencapsulated within a stealth liposomal nanocarrier. Interestingly, the obtained BSO/GA−Fe(II)@liposome is able to efficiently amplify intracellular oxidative stress via increasing •OH generation and reducing GSH biosynthesis. After chelating with 99mTc4+ radioisotope, such BSO/GA−Fe(II)@liposome could be tracked under in vivo single-photon-emission-computed-tomography (SPECT) imaging, which illustrates the time-dependent tumor homing of such liposomal nanoparticles after intravenous injection. With GA−Fe(II)-mediated •OH production and BSO-mediated GSH depletion, treatment with such BSO/GA−Fe(II)@liposome would lead to dramatically enhanced intratumoral oxidative stresses, which then result in remarkably improved therapeutic efficacies of concurrently applied chemotherapy or radiotherapy. This work thus presents the concise fabrication of biocompatible BSO/GA−Fe(II)@liposome as an effective adjuvant nanomedicine to promote clinically used conventional cancer chemotherapy and radiotherapy, by greatly amplifying the intratumoral oxidative stress.