Citation Context

...ess and cellular toxicity were detected from the presence of free radicals and peroxides, leading to antioxidant depletion and loss of cell viability [79]. Inflammatory responses were also C. Klumpp et al. / Biochimica et Biophysica Acta 1758 (2006) 404–412410reported on the same cell line by MWNT [78]. The mechanism is likely to be due to the production of reactive oxygen species, leading to the activation of the nuclear transcription factor-nB [77]. Moreover, CNT can activate the human serum complement system via the classical and the alternative pathway, generating proinflammatory peptides [80]. Studies on the biocompatibility of SWNT on HEK293 human embryonic kidney cells showed a cell growth inhibition via induction of apoptosis and decrease of cell adhesion ability [73]. Pristine nanotubes usually contain transition metal catalysts like iron or nickel, which could explain the generation of free radicals, however, in the case of the MWNT no iron was detected before cellular interaction. A comparative study on the toxicity of pristine and oxidized MWNT onto human Jurkat T leukemia cells has shown that the latter were more toxic [74]. CNT tend to aggregate in ropes, decreasing in aq...

Citation Context

...as stopped by adding 60 times volume of PBS solution containing 0.05 wt% Tween-20 protein stabilizers and 0.035 wt% ProClin 300. Complement system activation of the nanoparticles was assayed following manufacturer’s instructions. Zymosan was used as a positive control for the alternative pathway and terminal cascade. Complement system activation via the lectin pathway was assessed using the ALPCO Diagnostics kit (Salem, MA, USA). To assess the genuine activation of the complement system via the alternative pathway, human serum was diluted 1:1 by volume with Mg–EGTA buffer as described in Ref. [12]. The diluted human serum was incubated with lipid–polymer nanoparticles and incubated for 1 h at 37 C in a shaking incubator. The reaction was stopped as described above. The experiments described above were carried out in accordance with the ethical standards of the responsible committee on human experimentation (institutional or regional) and with the Helsinki Declaration of 1975, as revised in 1983. 2.4. Protein binding studies Lipid–polymer hybrid NPs were incubated with the diluted (1:1 volume) human serum or human plasma under gentle shaking of 80 rpm at 37 C for 1 h. After incubation...

Citation Context

...diately resuspended in PBS containing protease inhibitors as previously described [36]. Where indicated, serum was extracted from plasma according to the protocol described by Salvador-Morales et al. =-=[37]-=-. All chemical reagents were of the highest analytical grade available from Merck, unless otherwise specified. Nomenclature Throughout this paper, whole immunoglobulin proteins are designated as eithe...

Citation Context

...f ENM on innate immune responses The innate immune system plays a critical role in the protection against pathogens, damaged self-macromolecules and cells, and other foreign particles, including ENM (=-=Salvador-Morales et al., 2006-=-). When the physical and chemical barriers that prevent foreign substances from entering the body are overcome or evaded, the first cells that respond are phagocytes. Phagocytosis of ENM by macrophage...

Citation Context

... induce a reduction of macrophage phagocytosis was lower 3 The complement is formed by a group of proteins present in the blood, which interact to defend the body against cells recognized as foreign (=-=Salvador-Morales et al., 2006-=-).IRSST- Health Effects of Nanoparticles 27 for SWCNT (0.38 μg/cm 2 ) than for MWCNT and fullerenes (3.06 μg/cm 2 ). SWCNT and MWCNT were more toxic than quartz, which is considered to be a major hea...

Citation Context

...ng surfactant. By using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), Western Blotting, a novel technique of affinity chromatography based on carbon nanotube–Sepharose matrix =-=[1]-=- and electron microscopy data it was shown that SP-A and SP-D selectively bind to carbon nanotubes. The binding was Ca 2+ -ion dependent, and was variable between batches of nanotubes. It was therefor...