Study On The MPC(2-methacryloyloxy Ethyl Phosphorylcholine) Modified Single-walled Carbon Nanotubes And Its Bioeffects

During the2decades since the found of CNTs, it has been widely and deeply researched in relative areas because of its unique nano-structure and the unusual physicochemical, mechanical, and electrical properties. Subsequently, the greater possibilities for its potential application in biological and biomedical use were realized, which appealed a lot of researchers and soon became a focus of research. However, before CNTs could be really used in this area and fully exploited for commercial interests, it is an urgent issue to clarify the cytotoxicity of the CNTsThere is another concern well before the consideration of the CNTs’cytotoxicity, namely, the water solubility of the CNTs. Up till now, many methods have been proposed to solve this problem, the most effective way among them is using physical and chemical modification and functionalization.Given the premis above, the research in this article choosed2-methacryloyloxy ethyl phosphorylcholine (MPC) to modify Single-walled Carbon Nanotubes (SWCNTs) covalently to synthesis two kinds of water soluble modified SWCNTs, SWCNT-PC and SWCNT-PCn. SWCNT-PC is grafted by a small MPC moiety, while for SWCNT-PCn, the PCn moiety formed a chain structure attached on the SWCNTs. We further grafted fluorescein isothiocyanate (FITC) onto two modified SWCNTs to make these two samples fluorescent, labled SWCNT-PC-FITC and SWCNT-PCn-FITC.We investigated the cytotoxicity of the modified SWCNTs for three kinds of cell lines, Human Umbilical Vein Endothelial Cells (HUVEC), murine macrophage (RAW264.7) and murine fibroblast (L929). These cell lines are typical models widely used in studies of cytotoxicity, endocytosis, metabolism, proliferation and RNA expressions. It was found that the modified SWCNTs possess a relatively lower cytotoxicity for the three cell lines compared with prestine SWCNTs, moreover, the three cell lines exhibited different tolerance against the modified SWCNTs.In this work, fluorescence microscope was applied to observe the three cell lines incubated with SWCNT-PCn-FITC both at37℃and4℃. This experiment was performed in order to confirm the results of CCK-8assay and further invesitigate the mechanism of cytotoxicity and uptake of modified SWCNTs. Moreover, we tried to find the relationship between the SWCNTs cytotoxicity and its uptake mechanism, we found that the cytotoxicity of modified SWCNTs was underestimated in CCK-8assay, and the cytotoxicity was closely related with the uptake mechanism of SWCNTs.