Researchers have synthesised molybdenum disulfide nanosheets that are non-toxic to two types of rat cell lines, making them potentially useful for biomedical applications such as cell imaging and gene delivery1.

Previous studies had shown that such nanosheets are structurally similar to graphene and exhibit interesting optoelectronic and sensing properties. However, the biocompatibility of the nanosheets had not been assessed.

The researchers synthesised molybdenum disulfide nanosheets using a technique known as liquid exfoliation. They then exposed two types of cultured rat cells (pheochromocytoma cells and adrenal medulla endothelial cells) to various concentrations of the nanosheets.

There was no significant drop in the viability of the rat cells at any of the nanosheet concentrations used. Cell morphology and proliferation measurements revealed that cells did not die when incubated with the nanosheets. Finally, electrical impedance spectroscopy measurements showed that the nanosheets have negligible toxic effects on rat cells.

The scientists attributed the biocompatibility of the nanosheets to the fact that the edges of the nanosheets did not penetrate or cut the membranes of rat cells and hence did not induce cell death.

“The results show that the nanosheets could be used to deliver genes and image cells,” says Subbiah Alwarappan, one of the researchers.