Kong Chao-Ying,Luo Chu-Wen,Xu Ya-Jun,Shen Na,Tang Zhao-Hui
Given that platinum-based drugs are widely used clinically as chemotherapeutic agents, their severe toxic side effects have attracted significant attention. Consequently, the development of novel nanoprodrugs based on low-toxicity tetravalent platinum (Pt(IV)) complexes holds substantial research value. Herein, we discovered that coumarin derivatives exhibit inherent antitumor efficacy and significantly enhance superoxide anion radicals (•O 2 − ) generation in aqueous solutions under ultrasound (US) irradiation. Given that •O 2 − is known to mediate the reduction of Pt(IV) to divalent platinum (Pt(II)), we engineered an US-responsive dual-drug nanoprodrug (P-cisPt(IV)@5-MOP). This nanoprodrug was prepared by covalently conjugating Pt(IV) and methoxy polyethylene glycol hydroxyl (mPEG-OH) to a poly( l -glutamic acid) (PLG) carrier, followed by encapsulating coumarin derivatives. Under low-intensity US irradiation (1.5 W/cm 2 , 1 MHz, 10 min), P-cisPt(IV)@5-MOP achieved a Pt(IV) reduction rate of 91.4%. Furthermore, upon US exposure, its half-maximal inhibitory concentration (IC 50 ) against 4T1 breast cancer cells decreased dramatically from 25.7 µmol/L to 0.1 µmol/L. Remarkably, this system combined with US therapy yielded a tumor inhibition rate of 90.9%, with 40% of tumor-bearing mice achieving complete eradication of tumors, while exhibiting low systemic toxicity. Collectively, this work not only identifies a novel sonosensitizer capable of generating •O 2 − but also develops a new class of ultrasound-activatable Pt(IV) nanoprodrug.
Non-small cell lung cancer (NSCLC) represents the most prevalent form of lung cancer, exerting a substantial impact on global health. Cisplatin-based chemotherapy is the standard treatment for NSCLC, but resistance and severe side effects present significant clinical challenges. Recently, novel tetravalent platinum compounds have attracted significant interest. While numerous studies concentrate on their functional modifications and targeted delivery, tumor-induced platinum resistance is frequently overlooked. Previous tetravalent platinum compound demonstrated antitumor activity, yet proved ineffective against cells exhibiting resistance to cisplatin. In order to enhance the efficacy and potential applications of tetravalent platinum in NSCLC, a glutathione (GSH)-responsive albumin nanoquadrivalent platinum (HSA@Pt) have been constructed. In light of previous research into drug conjugation, this study was to develop a combined chemo-immunotherapy approach. The HSA@Pt demonstrated high efficacy and low toxicity, with targeted tumor accumulation. Furthermore, Ammonium Tetrathiomolybdate (TM) has been demonstrated to exert a synergistic inhibitory effect on ATPase Copper Transporting Beta (ATP7B) and Programmed Death Ligand 1 (PD-L1), impede platinum efflux, induce cellular stress, and activate antitumor immunity. The findings suggest HSA@Pt’s potential for clinical use and a novel chemo-immunotherapy strategy for NSCLC, enhancing the utility of established drugs through synergistic sensitization.
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