Multilayered stable 2D nano-sheets of TiNT MXene: synthesis, characterization, and anticancer activity.

Background: The biological activity of MXenes has been studied for several years because of their potential biomedical applications; however, investigations have so far been limited to 2D titanium carbides. Although monolayered TiNT MXene has been expected to have biological activity, experimental studies revealed significant difficulties due to obstacles to its synthesis, its low stability and its susceptibility to oxidation and decomposition.

Results: In this paper, we report our theoretical calculations showing the higher likelihood of forming multilayered TiNT structures during the preparation process in comparison to single-layered structures. As a result of our experimental work, we successfully synthesized multilayered TiNT MXene that was suitable for biological studies by the etching of the TiAlN MAX phase and further delamination. The biocompatibility of TiNT MXene was evaluated in vitro towards human skin malignant melanoma cells, human immortalized keratinocytes, human breast cancer cells, and normal human mammary epithelial cells. Additionally, the potential mode of action of 2D TiNT was investigated using reactive oxygen tests as well as SEM observations. Our results indicated that multilayered 2D sheets of TiNT showed higher toxicity towards cancerous cell lines in comparison to normal ones. The decrease in cell viabilities was dose-dependent. The generation of reactive oxygen species as well as the internalization of the 2D sheets play a decisive role in the mechanisms of toxicity.

Conclusions: We have shown that 2D TiNT in the form of multilayered nanoflakes exhibits fair stability and can be used for in vitro studies. These results show promise for its future applications in biotechnology and nanomedicine.