氧化铈(CeO2-x)由于其丰富的氧空位而在光热和催化性能方面表现良好。基于此,我们设计了一个热敏治疗纳米平台,以实现肿瘤中药物的连续循环释放。它可以解决肿瘤治疗过程中底物不足造成的局限性。简而言之,将CeO2-x和喜树碱(CPT)包裹在琼脂糖水凝胶中,可以通过CeO2-x的光热效应熔化。同时,局部温度升高提供光热处理,可以诱导肿瘤细胞凋亡。之后,释放CPT以损伤肿瘤细胞中的DNA以实现化学治疗。此外,CPT可以激活烟酰胺腺嘌呤二核苷酸氧化酶与O2反应以增加细胞内H2O2。之后,暴露的CeO2-x可以催化H2O2产生细胞毒性活性氧,用于化学动力学治疗。更重要的是,CeO2-x可以催化H2O2生成O2,并与CPT的催化作用相结合,构建底物自循环纳米酶系统。总的来说,这种自循环纳米平台释放了肿瘤微环境中的缺氧,并建立了多模式肿瘤治疗,达到了理想的抗肿瘤效果。
Cerium oxide (CeO2-x) performs well in photothermal and catalytic properties due to its abundance of oxygen vacancies. Based on this, we designed a thermosensitive therapeutic nanoplatform to achieve continuous circular drug release in tumor. It can solve the limitation caused by insufficient substrate in the process of tumor treatment. Briefly, CeO2-x and camptothecin (CPT) were wrapped in an agarose hydrogel, which could be melted by the photothermal effect of CeO2-x. At the same time, the local temperature increase provided photothermal treatment, which could induce the apoptosis of tumor cell. After that, CPT was released to damage the DNA in tumor cells to realize chemical treatment. In addition, CPT could active nicotinamide adenine dinucleotide oxidase to react with O2 to increase the intracellular H2O2. After that, the exposed CeO2-x could catalyze H2O2 to generate cytotoxic reactive oxygen species for chemodynamic therapy. More importantly, CeO2-x could catalyze H2O2 to produce O2, which could combine with the catalytic action of CPT to construct a substrate self-cycling nanoenzyme system. Overall, this self-cycling nanoplatform released hypoxia in the tumor microenvironment and built a multimode tumor treatment, which achieved an ideal antitumor affect.