The biocompatibility of nanomaterials has attracted much attention. Graphene oxide (GO) is a nanomaterial widely used in biomedicine, but its toxicity can not be ignored. In this study, the effect of GO on the blood system (the hemolysis rate, the fragility of erythrocyte, and acetylcholinesterase activity) was systematically investigated. The results showed that the hemolysis rate of erythrocytes was lower than 8% when the GO concentration was below 100 μg/mL (P<0.01). GO at low concentration levels (<5 μg/mL) had no significant effect on the fragility of erythrocytes, but GO at high concentration (10 μg/mL) increased the fragility of erythrocytes (P=0.01). Moreover, GO increased the activity of acetylcholinesterase on erythrocytes. The concentration of 20 μg/mL graphene oxide with the size >5 μm (LGO) increased the activity of acetylcholinesterase by 42.67% (P<0.05). Then molecular dynamics simulation was used to study how GO interacted with acetylcholinesterase and increased its activity. The results showed that GO was attached to the cell membrane, thus may provide an electronegative environment that helps the hydrolysate to detach from the active sites more quickly so as to enhance the activity of acetylcholinesterase.
Keywords: acetylcholinesterase; erythrocyte; graphite oxide; hemolysis rate; molecular dynamics simulation.