Magister Scientiae (Medical Bioscience) - MSc(MBS) / Graphene oxide (GO) is a single carbon layer, oxygen bearing graphene derivative, containing hydroxyl and carboxyl groups. Graphene oxide nanoparticles (GONPs) are promising nanomaterials for a variety of applications such as electrochemical analysis, adsorption of biomolecules, biosensors and drug and vaccine delivery systems. While these newly engineered nanoparticles hold great potential for developments in industry and medicine, the widespread use of these material will inevitably result in GO residues in the environment where they could possibly pose a risk to human and wildlife health. Interaction of the nanoparticles and biota can affect numerous biological processes. In humans they can affect any of the physiological systems such as the immune, endocrine, reproductive and cardiovascular systems. Although studies have indicated that GO exposure cause increased reactive oxygen species in cells, they mechanisms whereby GO act on the cell are still poorly understood. A few studies have investigated the effects of GONP and other graphene nanoparticle derivatives on the immune system. The aim of this study was to investigate the in vitro effects of GONPs on the immune system by the exposure of the murine macrophage cell line, RAW 264.7, to different concentrations of GONPs.