In vitro assessment of neurotoxicity and neuroinflammation of homemade MWCNTs

Multi walled carbon nanotubes (MWCNTs) activate pathways involved in cytotoxicity, genotoxicity and inflammation. Inhaled MWCNTs are translocated to extra pulmonary organs and their hydrophobicity allows them to cross the blood-brain barrier (BBB). Further exposure of central nervous system (CNS) occurs via olfactory neurons. Using differentiated SH-SY5Y, we studied the neurotoxicity and neuroinflammation of pristine and functionalised MWCNTs. ROS overproduction was dose- and time-dependent (P<0.01) and was related to mitochondrial impairment, DNA damage and decreased viability (P<0.05). Transcript levels of TNFα, IL-1β and IL-6 increased, as confirmed by an ELISA test. Raman spectra were acquired to assess MWCNT-cells interactions. The almost superimposable pro-oxidant activity of both CNTs could be imputable to excessive lengths with regard to the pristine MWCNTs and to the eroded surface, causing increased reactivity, with regard to functionalised MWCNTs. Considering the ease with which lightweight MWCNTs aerosolize and the increased production, the results underlined the potential onset of neurodegenerative diseases, due to unintentional MWCNT exposure.