Manganese oxide nanoparticles: the influence of manganese oxidation state on selective lysis of tumor cells

Further studies on the mechanism of intracellular induction of active oxygen species and selective oncolysis with metal oxide nanoparticles (NPs), as well as the discussion of alternative mechanisms of the NPs impact on tumor cells, are needed to introduce nanotechnologies into antitumor therapy. The paper concerns the inhibition of oxidation processes in tumor cells under the action of manganese oxide-based NPs (size 10–60 nm) as the mechanism of a tumor cell death. When manganese (II) hydroxide-based NPs enter the cells, they are oxidized with oxygen to Mn 4+ compounds; the oxidation processes being blocked in the tumor cells. Hence, the MnO NPs cytotoxicity can be due to the possible direct reduction of O 2 in the presence of manganese compounds in the cells.