1,721,017 research outputs found
Biocompatibility of multi-wall carbon nanotubes on human neuroblastoma cell line and effects of metal impurity and surface oxidation
No full textPC12 Interaction with Magnetic Nanotubes: Effects on Viability, Cell Differentiation and Cell Translocation Induced by a Magnetic Field
No full textIn this paper we used Multi Wall Carbon Nanotubes (MWCNTs) containing 3% of residuals and impurities of Fe, Al, and Zn. MWCNTs, by virtue of Fe at their tips, are able to respond to the effects of external magnetic fields. We demonstrated that MWCNTs interact with PC12 cells without compromising their viability and differentiation with outgrowth of neurites. We also document that when exposed to a magnetic field, both undifferentiated and differentiated PC12 cells cultured in CNT-containing medium solution are able to move towards the magnetic source
Influence of purity and surface oxidation on cytotoxicity of multiwalled carbon nanotubes with human neuroblastoma cells
No full textThere are conflicting data concerning the safety and biocompatibility of carbon nanotubes (CNTs). In some reports CNTs have been used for gene delivery without significant toxicity, whereas in others various cytotoxic effects were observed, including induction of intracellular reactive oxygen species (ROS), DNA damage, and apoptosis. Although it is clear that CNT production methods, purity, and functionalization treatments impact on biocompatibility, most of the published reports lack detailed characterization of the CNT samples used. We investigated the effect of various physicochemical features of multiwalled carbon nanotubes (MWCNTs) on toxicity and biocompatibility with cultured human neuroblastoma cells by using MTT, WST-1, Hoechst, and oxidative stress assays. In vitro experiments confirm that after 3 days of incubation with three different types of CNTs dispersed in Pluronic F127 solution, 0.01% cell viability is not affected and apoptosis and ROS are not induced in the SH-SY5Y cells. With prolonged cultures and continued propagation in the presence of MWCNTs, the loss of cell viability was minimal for pure MWCNTs (99% purity), but cell proliferation decreased significantly for 97% purity MWCNTs and acid-treated MWCNTs (97% purity, surface oxidation 8%); no intracellular ROS were detected. When the concentration of CNTs increases, purity and surface oxidation seem to affect cell viability (ED25 is 48, 34.4, and 18.4 mu g/mL, respectively, for 99% purity MWCNTs, 97% purity MWCNTs, and acid-treated 97% purity MWCNTs. Our results indicate that concentrations of 5-10 mu g/mL MWCNTs seem ideal for studies on the design and development of artificial MWCNT nanovectors for gene and drug therapy against cancer.From the Clinical Editor: With prolonged cultures, loss of cell viability was minimal for preparations with 99% purity, but significant adverse effects were detected with 97% purity and with acid-treated preparations. A concentrations of 5-10 mu g/mL of MWCNTs seems ideal for gene and drug therapy against cancer. (C) 2009 Elsevier Inc. All rights reserved.</p
Physicochemical properties affecting cellular uptake of carbon nanotubes
No full textCarbon nanotubes (CNTs) are widely used for biomedical applications as intracellular transporters of biomolecules owing to their ability to cross cell membranes. In this article, we survey the reported literature and results of our published work in an attempt to provide a rational view of the various CNT internalization mechanisms. Essentially three uptake mechanisms (phagocytosis, diffusion and endocytosis) have been reported in the literature. In addressing the subject of cellular internalization of CNTs, the unique physicochemical characteristics of CNTs that influence and drive the cell uptake pathway are considered. According to available evidence, the degree of dispersion, the formation of supramolecular complexes and the nanotube length are crucial factors in determining the exact mechanism of cellular uptake. In conclusion, phagocytosis appears to be the internalization pathway for CNT aggregates, bundles, cluster or single dispersed nanotubes 1μ m or more in length; endocytosis is the internalization mechanism for nanotubes forming supramolecular structures; and diffusion is the internalization mechanism for submicron CNTs that do not form supramolecular complexes. This information may be relevant to the rational design of CNT-based carriers for cell therapy
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