Reactive oxygen species (ROS) have the potential to act as signal carriers during the development of malignant tumors. At an appropriate concentration, ROSs tend to mediate cell growth and signal transduction.
But ROS are known to be a double-edged sword. By becoming surplus, ROS could oxidize proteins, damage the structure of DNA and cause cell apoptosis. In addition, ROS can induce inflammation at the tumor site, which further improves the immunogenicity of the tumor.
Thus, increasing the content of ROS in tumor sites has proven to be an effective technique for the treatment of cancer. Currently, methods of producing ROS via external stimuli, such as radiation sensitization, sonodynamic reaction, and photodynamic reaction, are severely limited by the depth of laser penetration, the range of irradiation of the external excitation, and radiation safety issues.
Due to these problems, chemo-dynamic therapy has progressed and received a great deal of attention. Chemiodynamic therapy uses excess H2O2 in the tumor microenvironment without the need for external energetic stimulation to produce ROS via the Fenton reaction.
But the existing therapeutic effect of chemiodynamic therapy is considered unsatisfactory. Indeed, the initiation of an efficient Fenton reaction requires an excess of H2O2 and coarse acidic conditions. Besides exogenous ROS production approaches, increasing the generation of endogenous ROS to slow tumor growth is another potential technique.
Interference with the mitochondrial electron transport chain could enhance the generation of ROS. But treating cancer only by increasing endogenous ROS is unsatisfactory, since it is difficult to effectively prevent tumor growth with a limited amount of endogenous ROS generated.
Thus, in the field of cancer therapy, it is difficult to create approaches for the selective generation of sufficient ROS in the absence of external energy stimulation under mild in vivo conditions.
In the latest research article published in the Beijing-based journal National scientific journal, researchers at the Changchun Institute of Applied Chemistry of the Chinese Academy of Sciences, China, designed an ROS generation device that reacts in cascade with a domino effect and in the absence of external stimulation for the particular generation many severe ROS storms at the tumor site.
Study co-authors Yang Liu, Yinghui Wang, Shuyan Song, and Hongjie Zhang discovered that the simple introduction of synthesized ZnO2@ Ce6 /[email protected]/ The BSA nanobomb in the tumor would induce a “domino effect”.
This in turn could activate the production of several storms ROS and Ca2+ overload, as well as effectively activating the systemic immune response while preventing the growth of primary tumors. In addition, tumor metastases can be effectively prevented by adjuvant treatment with anti-CTLA4 checkpoint blockers.
This study received financial support from the National Foundation of Natural Sciences of China, the Strategic Priority Research Program of the Chinese Academy of Sciences and the Youth Innovation Promotion Association of the Chinese Academy of Sciences.
Liu, Y., et al. (2021) Cascade reactive nanobomb with domino effect for synergistic anti-tumor therapies. National scientific journal. doi.org/10.1093/nsr/nwab139.