College of Animal Science and Technology, Northwest A&F University, Xinong Road 22nd, Yangling, 712100, Shaanxi, China.
J Nanobiotechnology. 2018 Apr 25;16(1):44. doi: 10.1186/s12951-018-0370-1.
Single-walled carbon nanotubes (SWCNTs) have many potential applications in various fields. Especially, the unique physicochemical properties make them as the prime candidates for applications in biomedical fields. However, biocompatibility of SWCNTs has been a major concern for their applications. In the study, biocompatibility of oxidized SWCNTs (O-SWCNTs) was assessed using Saccharomyces cerevisiae (S. cerevisiae) as a model organism.
Cell proliferation and viability were significantly changed after exposure to O-SWCNTs (188.2 and 376.4 mg/L) for 24 h. O-SWCNTs were internalized in cells and distributed in cytoplasm, vesicles, lysosomes and cell nucleus. The average O-SWCNTs contents in S. cerevisiae were ranged from 0.18 to 4.82 mg/g during the exposure from 0 to 24 h, and the maximum content was reached at 18 h after exposure. Both penetration and endocytosis were involved in the internalization of O-SWCNTs in S. cerevisiae, and endocytosis was the main pathway. Cellular structures and morphology were changed after exposure to O-SWCNTs, such as undulating appearance at the membrane, shrinking of the cytosol, increased numbers of lipid droplets and disruption of vacuoles. ROS and antioxidant enzymes activities were observably changed following exposure. For the treatment at 376.4 mg/L, 20.8% of the total cells was undergone apoptosis. Decrease of mitochondrial transmembrane potential and leakage of cytochrome c from mitochondria were observed after exposure. Moreover, expression levels of apoptosis-related genes were significantly increased.
O-SWCNTs can internalize in S. cerevisiae cells via direct penetration and endocytosis, and distribute in cytoplasm, vesicles, lysosomes and cell nucleus. Besides, O-SWCNTs (188.2 and 376.4 mg/L) can induce apoptosis in S. cerevisiae cells, and oxidative stress is involved in activation of the mitochondria-dependent apoptotic pathway.
单壁碳纳米管（SWCNTs）在各个领域都有许多潜在的应用。特别是，它们独特的物理化学性质使它们成为生物医学领域应用的首选。然而，SWCNTs 的生物相容性一直是它们应用的主要关注点。在这项研究中，以酿酒酵母（Saccharomyces cerevisiae）作为模式生物，评估了氧化 SWCNTs（O-SWCNTs）的生物相容性。
暴露于 O-SWCNTs（188.2 和 376.4 mg/L）24 小时后，细胞增殖和活力明显改变。O-SWCNTs 被细胞内化，并分布在细胞质、囊泡、溶酶体和细胞核中。在暴露 0 至 24 小时期间，酿酒酵母中的平均 O-SWCNTs 含量范围为 0.18 至 4.82 mg/g，暴露 18 小时后达到最大值。在酿酒酵母中，O-SWCNTs 的内化既涉及穿透也涉及内吞作用，内吞作用是主要途径。暴露于 O-SWCNTs 后，细胞结构和形态发生变化，如细胞膜起伏、细胞质收缩、脂质滴数量增加和液泡破裂。暴露后 ROS 和抗氧化酶活性明显改变。在 376.4 mg/L 的处理下，有 20.8%的总细胞发生凋亡。暴露后观察到线粒体跨膜电位下降和细胞色素 c 从线粒体漏出。此外，凋亡相关基因的表达水平显著增加。
O-SWCNTs 可以通过直接穿透和内吞作用进入酿酒酵母细胞，并分布在细胞质、囊泡、溶酶体和细胞核中。此外，O-SWCNTs（188.2 和 376.4 mg/L）可诱导酿酒酵母细胞凋亡，氧化应激参与激活线粒体依赖性凋亡途径。
