Effect of graphene oxide nanoparticles on viability of BAP3 hybridoma cells

Graphene oxide (GO) is a promising material, which is likely to find applications in the fields of medicine and biotechnology. However, the current knowledge of its influence on human organism is limited. Even less information is available on the effects of GO on the cell lines widely used in biotechnology. The aim of this work is to describe the interaction between GO nanoparticles and BAP3 hybridoma cells which produce anti-human-PSG1 IgG, in vitro. We studied the effect of GO nanoparticles on cell viability and the intensity of internalization (adhesion) of nanoparticles by the cells. We used GO nanoparticles of different size, with surface being functionalized by linear or branched PEG (GO-PEG). The PEG coating level was 20% (by mass). The following nanoparticle concentrations were used: 5 μg/mL and 25 μg/mL. The BAP3 cells were cultured in a 48-well cell culture plates in serum-free DCCM-1 media in the presence of GO nanoparticles. The cells were cultured for 24 hours at 37 °С and 5% СО₂. Cell viability was assessed by a flow cytometer utilizing Zombie Aqua (ZA) staining. Internalization (adhesion) of nanoparticles was monitored using a flow cytometer by GO fluorescense in the samples (λ_ex = 488 nm). Moreover, interactions between hybridoma cells and GO nanoparticles were visualized by EVOS M5000 visualization system, which included an inverted fluorescent microscope.

We demonstrated that GO nanoparticles possess a cytotoxic effect when applied at high concentration (25 μg/mL). The highest cytotoxic effect is caused by GO nanoparticles coated with linear PEG. The degree of nanoparticle internalization (adhesion) was shown to be significantly lower when the particles were present at lower (5 μg/mL) concentration. Internalization (adhesion) of nanoparticles of smaller size was more abundant. Furthermore, these nanoparticles were shown to have a stronger cytotoxic effect compared to larger particles. In general, cytotoxicity of GO nanoparticles decreases with increasing size, which is especially evident if the fact that the mean effective diameter of the nanoparticles coated with branched PEG is considered larger than their linear PEG-coated counterparts. The data obtained allow us to draw a correlation between the cytotoxic effect of GO nanoparticles and the level of their internalization (adhesion) by the cells. In general, this work concerns some novel aspects of interaction between GO nanoparticles and hybridoma cells.