Graphene oxide has a neuroprotective effect against glutamate-induced excitoxicity on B35 neuroblastoma cell line

Abstract

Glutamate is one of the main excitatory neurotransmitters in the central nervous system (CNS), involved in neural transmission, development, differentiation and plasticity. It plays a vital role in neural pathways for cognition, memory and learning, and synapse induction and elimination during development, cell migration, differentiation and death. Glutamate is continuously released from neurons and uptaken from extracellular fluid. AbstractObjectives: Graphene is a quasi-two-dimensional material with unique electrical and chemical properties. In terms of biomedical applications of graphene, nervous system would be an ideal breakthrough model because neural cells are electroactive. Extreme glutamate concentrations cause excitotoxicity. In this study, we aimed to investigate if graphene can increase the resistance to glutamate stress in B35 rat neuroblastoma cells as a cultured cell model for central nervous system neurons.Methods: B35 neuroblastoma cells were grown in DMEM-F12 growth medium containing 10% fetal bovine serum. Graphene oxide (GO) powder was coated onto glass slides with chitosan as a thin film. B35 cells were cultured on GO films. Cells cultivated on glass slides were used as controls. After 24 h of cell culture, L-glutamine induced excitotoxicity was imposed on B35 cells. After 24 h of glutamate-induced stress, cell morphology was examined by scanning electron microscopy. Cell viability was measured with MTT assay. Results:The effects of glutamate stress on cell viability were visible as early as 1 h. The cell viability on GO films was higher than that on glass slides, and cells recovered from stress within 6 h on GO surfaces. After 24 h, viability on glass surfaces was 54% lower than that on GO surfaces; these findings were supported with cell morphology observations. Conclusion:The results of this study showed that GO has a protective role in reducing glutamate-induced excitotoxicity in B35 cell culture, indicating a potential use of GO for treatment of excitotoxicity induced neurodegenerative diseases.