Laboratory Studies Of The Cell Biological Effects Of Carbon Nanotubes

Carbon nanotubes(CNTs) are one of the most promising materials in nanotechnology, which have unique and excellent properties in mechanical, electronics, optics and so on, which are widely used in information storage, biomedicine, materials science and other fields. The synthesis methods of carbon nanotubes include arc discharge, laser evaporation and chemical vapor deposition(CVD) and so on. Especially,chemical vapor deposition became the most widely used synthesis method of present study for its simple equipment and the whole reaction process is easy to control. With the Broad use of carbon nanotubes provide convenience for people’s daily life, we also need to consider the potential biological effects, and the possible damage. So this thesis mainly to explore the biological effects of carbon nanotubes from three aspects:At first, we studied the cytotoxicity of different cell lines of different sizes of carbon nanotubes into different dispersants, the cell viability is highly related to the incubate time and the concentration of CNTs, with the increase of incubation time and concentration the cell viability will be greatly reduced. For the same kind of cells, the toxicity of NM 401 CNTsis the biggest under the same conditions, which may be related to the length of it. And in terms of the same type carbon nanotubes, different cell lines have different tolerance, 16 HBE > d-THP-1. Moreover,different dispersant also have effects to cell viability, but it is not the main factor. In this study, we investigate factors of cell viability, which can provide instructive methods and reference to evaluate the biological effects of other nanomaterials.Secondly, we focused on the NM 401 CNTs, which of greatest toxicity, to have a further research, explore the nature of its toxicity from molecules level. We found that NM 401 CNTs can stimulate the human umbilical endothelial cells(HUVECs) to produce reactive oxygen species(ROS),and with the increase of incubation time and concentration levels, the produced ROS increased with cell toxicity, so the higher level of intracellular ROS, the greater the cell toxicity.Finally, we studied the dysfunction of human umbilical endothelial cells, induced by NM 401 CNTs. Along with the generation of reactive oxygen species in the cell, the oxidative stress-related genes GPX-1expression significantly up-regulated, moreover, adhesion molecules VCAM-1, ICAM-1 and monocyte chemotactic protein 1(MCP-1) also significantly up-regulated, with the help of them the adhesion of monocytes to the surface of HUVECs increased obviously, which may have the risk lead to atherosclerosis. Therefore, we studied themechanism of it, and found that the NF-KB signal pathway was activated.This thesis provided a good safety evaluation basis for the use of CNTs in biomedicine.