A new drug carrier with oxygen generation function for modulating tumor hypoxia microenvironment in cancer chemotherapy.

Hypoxia is the main characteristic of tumor microenvironment, and the one of the key factors that cause the drug resistance of cancer cells for chemotherapy. Anticancer drug such as DOX cannot react with sufficient oxygen to produce reactive oxygen species (ROS) in hypoxic environment, which affects the therapeutic efficiency of the drug. In this work, we constructed a multi-functional nano-carrier (named as FeSiAuO) containing Fe3O4, mesoporous SiO2 and Au2O3 with magnetic, large surface ratio and light induced oxygen production properties. The Au2O3 may decompose into oxygen (O2) and Au under the light irradiation to improve the oxygen concentration of the microenvironment of cancer cells, which increases the sensitivity of cancer cells to drug (DOX), reduces the drug resistance, and effectively exerts the anticancer effect of DOX. Meanwhile, the release of the as-loaded DOX molecule from the porous of SiO2 will be also promoted under light irradiation in diverse pH conditions. With the helping of the magnet effect of the Fe3O4, the DOX can be also targeted delivered to the tumor site under the magnetic field. All of above results were thoroughly examined by the cell and small animal assays, which demonstrate that the FeSiAuO can be served as the multifunctional drug nano-carrier to achieve the targeted high-efficient cancer therapy.