Self-Propelled Autonomous Mg/Pt Janus Micromotor Interaction with Human Cells

Magnesium (Mg)-based micromotors have attracted considerable attention as they are capable of moving in water and human blood plasma without external fuels. It has also been demonstrated that they have potential for drug delivery in mouse stomach. However, their biocompatibility and cytotoxicity to human cells have yet to be studied. Therefore, we performed cytotoxicity study of Mg/Pt Janus micromotors with human lung carcinoma epithelial cells (A₅49), human breast cancer cells (MCF-7), human embryonic kidney cells (HEK-293), human liver carcinoma cells (HepG₂) and human cervical cancer cells (HeLa). The highest concentration of micromotors tested, 200 µg mL−1, drastically induced a high toxic effect on the cells and reduced the cell viability to below 60%. This shows while Pt/Au nanomachines were found to be safe previously, this is not the case of the Mg/Pt micromachines.