MnO2 Motor: A Prospective Cancer-Starving Therapy Promoter.

Here, a tumor-targeted MnO2 motor nanosystem (designed as MG/HA) was constructed by the assembly of glucose oxidase (GOD), manganese dioxide (MnO2), and glycoprotein CD44-targeting polymer hyaluronic acid (HA) to elevate cancer-starving therapy efficacy in solid tumor. Upon the specific uptake of MG/HA by CD44 overexpressed cancer cells, GOD catalyzed the oxidation of glucose into gluconic acid and hydrogen peroxide (H2O2) accompanying the consumption of oxygen (O2). Meanwhile, MnO2 would react with H2O2 and acid to generate O2, which is in turn supplied to the glucose-depletion process, running like a loop. As a result, MnO2 is displayed as a motor to promote the rate of glucose depletion that contributed to the starving therapy. In contrast to G/HA, MG/HA could not only achieve effective glucose consumption to depress cancer progression, but also alleviate hypoxia and reduce the expression of Glut1 to inhibit the metabolism for further restraining the tumor aggressiveness and metastasis. The concept of MnO2 motor shows a promising prospect to overcome the restriction of the starving therapy.