Induction of oxidative stress and cytotoxicity by carbon nanomaterials is dependent on physical properties.

Rama Narsimha Reddy, A; Narsimha Reddy, Y; Himabindu, V; Rama Krishna, D

In this study, we investigated the mechanisms involved in multi-wall carbon particles/nanomaterials (MWCNM) induced cytotoxicity using human embryonic kidney (HEK293) cells and to assess the effect of physicochemical properties on the cytotoxicity and oxidative stress induced by the carbon nanomaterials (CNM). To elucidate the possible mechanisms of CNM-induced cytotoxicity, cell viability (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide [MTT assay]), cell membrane damage (lactate dehydrogenase enzyme [LDH] assay), reduced glutathione (GSH), interleukin-8 (IL-8) and lipid peroxidation levels were quantitatively assessed under carbon nanomaterials exposed (48 h) conditions. Exposure of different sizes of four CNM at dosage levels between 3 and 300 μg/mL decreased cell viability in a concentration- and size-dependent manner. Exposure of CNM (10-100 μg/mL) to HEK cells resulted in size-, surface area- and concentration-dependent cell membrane damage, increased production of IL-8, increased thiobarbituric acid reactive substances (TBARS) and decreased intracellular glutathione levels. In summary, the physical properties of carbon nanoparticles may alter the CNM-induced concentration-dependent cytotoxicity and oxidative stress.