Nano–Bio Interaction between Graphite Oxide Nanoparticles and Human Blood Components

We investigated the effect of graphite oxide (GO) nanoparticles, which are an emerging nanomaterial with potential applications as drug-delivery nanocarriers, on human blood cells and plasma proteins. Graphite oxides were successfully prepared by oxidizing graphite with potassium permanganate and sulfuric acid. Powder X-ray diffraction patterns, FTIR, and Raman spectra show that the oxidation of graphite worked well and yielded GO nanolayers. To evaluate the interaction of GO with human blood components, we studied its hemolytic effect and protein binding kinetics. The nanoparticles did not show any significant hemolytic effect during 30 min at a very high concentration of 10 mg/mL, showing high compatibility with human blood. The interaction between GO nanoparticles and human blood cells was visualized with optical microscopy. Some nanoparticles were found at the periphery of blood cells, however, significant damages or morphological changes of blood cells upon exposure to nanoparticles were not detected. When we treated GO nanoparticles with plasma proteins, such as human serum albumin, γ-immunoglobulin, and fibrinogen, they showed concentration-dependent binding behavior, and the binding constant is comparable with other biocompatible nanoparticles.