Multilayered stable 2D nano-sheets of Ti2NTx MXene: synthesis, characterization, and anticancer activity

A Szuplewska,A Rozmysłowska-Wojciechowska,M Popielski,A M Jastrzębska,S Poźniak,M Birowska,M Chudy,L Chlubny,A Olszyna,J A Majewski,W Ziemkowska,T Wojciechowski,D Moszczyńska

doi:10.1186/s12951-019-0545-4

Abstract

BackgroundThe 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 Ti2NTx 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.ResultsIn this paper, we report our theoretical calculations showing the higher likelihood of forming multilayered Ti2NTx structures during the preparation process in comparison to single-layered structures. As a result of our experimental work, we successfully synthesized multilayered Ti2NTx MXene that was suitable for biological studies by the etching of the Ti2AlN MAX phase and further delamination. The biocompatibility of Ti2NTx 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 Ti2NTx was investigated using reactive oxygen tests as well as SEM observations. Our results indicated that multilayered 2D sheets of Ti2NTx 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.ConclusionsWe have shown that 2D Ti2NTx 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.

Highlights

The biological activity of MXenes has been studied for several years because of their potential biomed‐ ical applications; investigations have so far been limited to 2D titanium carbides
After hydrofluoric acid (HF) etching, the MXene was subjected to a two-step delamination process, which allowed 2D sheets of Ti2NTx MXene (Fig. 2c) to be obtained
The Fourier transformation (FFT) image together with the related IFFT extraction of the multilayered structure of the obtained 2D sheets of Ti2NTx MXene are presented in Fig. 2e and f, respectively

Summary

Introduction

The biological activity of MXenes has been studied for several years because of their potential biomed‐ ical applications; investigations have so far been limited to 2D titanium carbides. The most recent members of this group are early transition metal carbides, nitrides, and carbonitrides called MXene phases They were first discovered in 2011 during studies on the application of MAX phases in supercapacitors by Naguib, Barsoum, and Gogotsi from Drexel University, USA [10]. This new class of nanomaterials has so far demonstrated significant potential in many applications, such as energy storage [11], ceramic matrix composites [12,13,14], and macromolecules’ adsorption [15]. Due to the fact that the MXenes are developing much more dynamically in comparison to other 2D materials apart from graphene, they were considered as the most interesting and bringing the greatest innovation potential among their analogs [21]

Methods

Results

Conclusion