Multiwalled Carbon Nanotube-Superoxide Dismutase Conjugate Towards Alleviating Induced Oxidative Stress

Superoxide dismutase (SOD), an antioxidative enzyme, was covalently immobilized onto oxidized multi-walled carbon nanotubes (MwCNTs) using diimide activated amidation reaction. MwCNT(SOD) conjugates with high aqueous dispersible nature were obtained and characterized further using field emission scanning electron microscopy and Fourier transformed infrared spectroscopy. The synthesized conjugates even after 96 h incubation time period were found to retain significant superoxide anion scavenging activity. The synthesized MwCNT(SOD) conjugate were found to no significant toxicity in limited doses. Conditions for oxidative stress in human skin HaCat cells were optimized using H2O2 (1 mM) as an external stress factor and subsequently anti-oxidative response of synthesized MwCNT(SOD) conjugate was analyzed. Upon incubation with oxidative stress induced HaCat cells, MwCNT(SOD) conjugates were found to alleviate the increased oxidative stress indicating its enhanced uptake and efficient antioxidative activity. Low level of reactive oxygen species and increased SOD activity in HaCat cells post treatment with MwCNT(SOD) conjugate further confirms the antioxidative activity of SOD enzyme in conjugation with MwCNTs which acts as an efficient intracellular drug delivery vehicles.