Technology Transfer Office, Usak University, Usak, Turkey.
Department of Biology, Faculty of Science and Literature, Cukurova University, Adana, Turkey.
Microsc Res Tech. 2022 Sep;85(9):3193-3206. doi: 10.1002/jemt.24177. Epub 2022 Jun 9.
Herein, single-walled carbon nanotubes (SWCNTs) were synthesized by the thermal chemical vapor deposition (CVD) method, and characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Raman spectroscopy, dynamic light scattering (DLS), and thermo-gravimetric analysis (TGA). The results indicated that obtained nanotubes were SWCNTs with high crystallinity and their average diameter was 10.15 ± 3 nm. Allium cepa ana-telophase and comet assays on the root meristem were employed to evaluate the cytotoxic and genotoxic effects of SWCNTs by examining mitotic phases, mitotic index (MI), chromosomal aberrations (CAs), and DNA damage. A. cepa root tip cells were exposed to SWCNTs at concentrations of 12.5, 25, 50, and 100 μg/ml for 4 h. Distilled water and methyl methanesulfonate (MMS, 10 μg/ml) were used as the negative and positive control groups, respectively. It was observed that MIs decreased statistically significantly for all applied doses. Besides, CAs such as chromosome laggards, disturbed anaphase-telophase, stickiness and bridges and also DNA damage increased in the presence of SWCNTs in a concentration-dependent manner. In the molecular docking study, the SWCNT were found to be a strong DNA major groove binder showing an energetically very favorable binding free energy of -21.27 kcal/mol. Furthermore, the SWCNT interacted effectively with the nucleotides on both strands of DNA primarily via hydrophobic π and electrostatic interactions. As a result, cytotoxic and genotoxic effects of SWCNTs in A. cepa root meristematic cells which is a reliable system for assessment of nanoparticle toxicology were demonstrated in this study. RESEARCH HIGHLIGHTS: SWCNT synthesis with high crystallinity was achieved by the CVD method. Cytotoxic and genotoxic influences of SWCNTs were investigated. Allium and Comet tests were utilized. For all of the applied concentrations of SWCNTs, the MIs significantly decreased. SWCNTs were found genotoxic.
本文采用热化学气相沉积（CVD）法合成了单壁碳纳米管（SWCNT），并通过扫描电子显微镜（SEM）、能谱（EDX）、透射电子显微镜（TEM）、拉曼光谱、动态光散射（DLS）和热重分析（TGA）对其进行了表征。结果表明，所得到的纳米管是具有高结晶度的 SWCNT，其平均直径为 10.15±3nm。采用洋葱根尖细胞有丝分裂末期和彗星试验，通过检查有丝分裂阶段、有丝分裂指数（MI）、染色体畸变（CA）和 DNA 损伤，评估 SWCNT 的细胞毒性和遗传毒性效应。将洋葱根尖细胞暴露于浓度为 12.5、25、50 和 100μg/ml 的 SWCNT 中 4 小时。蒸馏水和甲磺酸甲酯（MMS，10μg/ml）分别作为阴性和阳性对照组。结果发现，所有应用剂量的 MI 均呈统计学显著降低。此外，随着 SWCNT 浓度的增加，CA 如染色体滞后、分裂后期-末期紊乱、粘连和桥接以及 DNA 损伤也呈浓度依赖性增加。在分子对接研究中，发现 SWCNT 是一种强 DNA 大沟结合物，具有-21.27 kcal/mol 的非常有利的结合自由能。此外，SWCNT 与 DNA 两条链上的核苷酸有效相互作用，主要通过疏水π和静电相互作用。因此，本研究证明了 SWCNT 在洋葱根尖分生细胞中的细胞毒性和遗传毒性效应，洋葱根尖分生细胞是评估纳米颗粒毒理学的可靠系统。研究亮点：采用 CVD 法合成具有高结晶度的 SWCNT。研究了 SWCNT 的细胞毒性和遗传毒性影响。采用了洋葱和彗星试验。所有应用浓度的 SWCNT 均显著降低了 MI。SWCNT 被发现具有遗传毒性。
