Investigation of functionalized and protein loaded carbon nanotubes in biological environment

Carbon nanotubes which are the popular nanoparticles of recent years have started to be used in drug or molecule transport, tumor treatment, nano-size skeletons in tissue engineering and in biosensors. The formation of a tubular graphene structure is single-walled carbon nanotube and nested graphene tubes are multi-walled carbon nanotubes. Since multi-walled carbon nanotubes gave more positive results in biocompatibility tests, molecular / drug binding-release mechanisms and biocompatibility of these structures were investigated in our study for multi-walled carbon nanotubes. The nanotubes were tested for toxicity in different cell lines. During toxicity tests, MTT and XCelligence real-time cell analysis assays were performed; fluorescence microscopy images were taken and compared with control groups. Short-term and long-term toxicity have been investigated in Ceanorhabditis Elegans. It has been observed that nematodes, which tend to escape from toxic materials, do not escape from nanotubes, lay their eggs on them, and even eat nanotubes in the medium. It was observed that the nematodes applied with high amount of nanotubes thickened and their survival did not change. Nanotubes were characterized by scanning electron microscope and high resolution transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectrophotometer, thermogravimetric analysis methods. The effects of bovine serum albumin, diphtheria toxin and doxorubicin on different mammalian cell lines (MDA-MB-231, HT-29, HUVEC and NIH-3T3) were investigated. Diphteria toxin loaded carbon nanotubes was transported into receptor-free mouse-derived 3T3 cells, cellular uptake confirmed by western blot and ADP-ribosylation experiments. It was corrected that diphteria toxin were carried into the cell and fragment-A which is enzymatically active part of the toxin was ADP-ribosylated the NAD in the presence of eukaryotic elongation factor 2.