In vitro hemocompatibility and toxic mechanism of graphene oxide on human peripheral blood T lymphocytes and serum albumin.
Graphene oxide (GO) has shown tremendous application potential as a biomedical material. However, its interactions with blood components are not yet well understood. In this work, we assess the toxicity of pristine GO (p-GO) and functionalized GO (GO-COOH and GO-PEI) to primary human peripheral blood T lymphocytes and human serum albumin (HSA), and also study the underlying toxic mechanism. Our results indicate that p-GO and GO-COOH have good biocompatibility to T lymphocytes at the concentration below 25 μg mL(-1), but notable cytotoxicity above 50 μg mL(-1). By contrast, GO-PEI exhibits significant toxicity even at 1.6 μg mL(-1). Further investigations show that although p-GO does not enter into the cell or damage the membrane, its presence leads to the increase in reactive oxygen species (ROS), moderate DNA damage, and T lymphocyte apoptosis. Interestingly, little effect on T lymphocyte immune response suppression is observed in this process despite p-GO inflicting cell apoptosis. The toxic mechanism is that p-GO interacts directly with the protein receptors to inhibit their ligand-binding ability, leading to ROS-dependent passive apoptosis through the B-cell lymphoma-2 (Bcl-2) pathway. Compared with p-GO, GO-COOH exhibits a similar toxic effect on T lymphocytes except keeping a normal ROS level. A proposed toxic mechanism is that GO-COOH inhibits protein receptor-ligand binding, and passes the passive apoptosis signal to nucleus DNA through a ROS-independent mechanism. On the other hand, GO-PEI shows severe hematotoxicity to T lymphocytes by inducing membrane damage. For plasma protein HSA, the binding of GO-COOH results in minimal conformational change and HSA's binding capacity to bilirubin remains unaffected, while the binding of p-GO and GO-PEI exhibits strong toxicity on HSA. These findings on the interactions of two-dimensional nanomaterials and biological systems, along with the enquiry of the mechanisms, would provide essential support for further safety evaluation of the biomedical applications of GO.
Key Laboratory for Nano-Bio Interface Research, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences , Suzhou 215123, China.
Zhijia
Z
Ding
Zhijun
Z
Zhang
Hongwei
H
Ma
Yanyan
Y
Chen
D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects; D006108:Graphite / Q000009:adverse effects*; D006801:Humans; D010087:Oxides / Q000009:adverse effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012709:Serum Albumin / Q000187:drug effects*; D013601:T-Lymphocytes / Q000187:drug effects*
D010087:Oxides; D017382:Reactive Oxygen Species; D012709:Serum Albumin; D006108:Graphite
T lymphocytes; graphene oxide; hemocompatibility; plasma proteins; toxic mechanism