Potential Biosafety of Mxenes: Stability, Biodegradability, Toxicity and Biocompatibility

MXenes are two-dimensional nanomaterials with unique properties that are widely used in various fields of research, mostly in the field of energy. Fewer publications are devoted to MXene application in biomedicine and the question is: are MXenes safe for use in biological systems? The sharp edges of MXenes provide the structure of "nanoknives" which cause damage in direct physical contact with cells. This is effectively used for antibacterial research. However, on the other hand, most studies in cultured cells and rodents report that they do not cause obvious signs of cytotoxicity and are fully biocompatible. The aim of our review was to consider whether MXenes can really be considered non-toxic and biocompatible. Often the last two concepts are confused. We first reviewed aspects such as the stability and biodegradation of MXenes, and then analyzed the mechanisms of toxicity and their consequences for bacteria, cultured cells, and rodents, with subsequent conclusions regarding their biocompatibility.