Thiophene-based water-soluble C₇₀ fullerene derivatives as novel antioxidant agents.

Fullerenes are one of the most popular nanomaterials, and C₇₀ fullerene is the second most common fullerene after C₆₀ buckminsterfullerene. Minor modification of fullerenes derivatives can change their biological effects and antioxidant properties. A plethora of water-soluble derivatives can be synthesised based on buckminsterfullerenes. In the present study, we synthesised three water-soluble C₇₀ fullerene derivatives with thiophene-based solubilising addends and tested their cytotoxicity and the transcriptional activity of genes, which regulate an oxidative metabolism. Aliphatic chain length in the structure of the solubilising addend of the water-soluble fullerene derivative has been varied, and we revealed that a longer chain resulted in more pronounced antioxidant activity. Thus, the surface modification enhances the antioxidant properties of the compound and changes the nanoparticles impact on the genetic apparatus of the cell. Interestingly, even slight modifications of the functional addend's structure can significantly affect the final cell response. The data obtained can be harnessed to develop novel and efficient medications for the management of ischaemia, stress-related conditions, the prevention of ageing, and the resolution of other practical healthcare challenges.