Cytotoxicity Effects of Graphene and Single-Wall Carbon Nanotubes in Neural Phaeochromocytoma-Derived PC12 Cells

TLDR

Graphitic nanomaterials such as graphene layers and single‑wall carbon nanotubes are promising for biomedical use, yet their biological effects remain largely unknown. Shape and concentration of graphene and single‑wall carbon nanotubes dictate their cytotoxicity in PC12 cells, with graphene showing higher metabolic activity at low doses, while SWCNT elicit greater LDH release, ROS production, and caspase‑mediated apoptosis, highlighting shape as the primary determinant of their biological activity.

Abstract

Graphitic nanomaterials such as graphene layers (G) and single-wall carbon nanotubes (SWCNT) are potential candidates in a large number of biomedical applications. However, little is known about the effects of these nanomaterials on biological systems. Here we show that the shape of these materials is directly related to their induced cellular toxicity. Both G and SWCNT induce cytotoxic effects, and these effects are concentration- and shape-dependent. Interestingly, at low concentrations, G induced stronger metabolic activity than SWCNT, a trend that reversed at higher concentrations. Lactate dehydrogenase levels were found to be significantly higher for SWCNT as compared to the G samples. Moreover, reactive oxygen species were generated in a concentration- and time-dependent manner after exposure to G, indicating an oxidative stress mechanism. Furthermore, time-dependent caspase 3 activation after exposure to G (10 μg/mL) shows evidence of apoptosis. Altogether these studies suggest different biological activities of the graphitic nanomaterials, with the shape playing a primary role.