School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore.
Toxicol Sci. 2012 Mar;126(1):149-61. doi: 10.1093/toxsci/kfr332. Epub 2011 Dec 8.
Because of their attractive chemical and physical properties, graphitic nanomaterials and their derivatives have gained tremendous interest for applications in electronics, materials, and biomedical areas. However, few detailed studies have been performed to evaluate the potential cytotoxicity of these nanomaterials on living systems at the molecular level. In the present study, our group exploited the isobaric tagged relative and absolute quantification (iTRAQ)-coupled two-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS) approach with the purpose of characterizing the cellular functions in response to these nanomaterials at the proteome level. Specifically, the human hepatoma HepG2 cells were selected as the in vitro model to study the potential cytotoxicity of oxidized single-walled carbon nanotubes (SWCNTs) and graphene oxide (GO) on the vital organ of liver. Overall, 30 differentially expressed proteins involved in metabolic pathway, redox regulation, cytoskeleton formation, and cell growth were identified. Based on the protein profile, we found oxidized SWCNTs induced oxidative stress and interfered with intracellular metabolic routes, protein synthesis, and cytoskeletal systems. Further functional assays confirmed that oxidized SWCNTs triggered elevated level of reactive oxygen species (ROS), perturbed the cell cycle, and resulted in a significant increase in the proportion of apoptotic cells. However, only moderate variation of protein levels for the cells treated with GO was observed and functional assays further confirmed that GO was less cytotoxic in comparison to oxidized SWCNTs. These finding suggested that GO was more biocompatible and could be a promising candidate for bio-related applications.
由于其具有吸引人的化学和物理性质，石墨纳米材料及其衍生物在电子、材料和生物医学等领域的应用引起了极大的兴趣。然而，很少有详细的研究评估这些纳米材料在分子水平上对活细胞的潜在细胞毒性。在本研究中，我们小组利用同位标记相对和绝对定量（iTRAQ）联合二维液相色谱-串联质谱（2D LC-MS/MS）方法，目的是在蛋白质组水平上描述这些纳米材料对细胞功能的影响。具体来说，选择人肝癌 HepG2 细胞作为体外模型，研究氧化单壁碳纳米管（SWCNTs）和氧化石墨烯（GO）对肝脏重要器官的潜在细胞毒性。总的来说，鉴定出了 30 种差异表达蛋白，这些蛋白涉及代谢途径、氧化还原调节、细胞骨架形成和细胞生长。基于蛋白质图谱，我们发现氧化 SWCNTs 诱导氧化应激并干扰细胞内代谢途径、蛋白质合成和细胞骨架系统。进一步的功能分析证实，氧化 SWCNTs 引发了活性氧（ROS）水平的升高，扰乱了细胞周期，并导致凋亡细胞的比例显著增加。然而，与氧化 SWCNTs 相比，GO 处理的细胞的蛋白水平仅发生适度变化，并且功能分析进一步证实 GO 的细胞毒性比氧化 SWCNTs 低。这些发现表明 GO 更具生物相容性，可能是生物相关应用的有前途的候选物。
