Studies on cytotoxicity of nickel ions using C3H10T1/2 fibroblast cells

Polyampholyte-Wrapped Carbon Nanotubes: Preparation and Internalization by Embryonic Fibroblast Cells

The cytotoxicity and cellular uptake of carbon nanotubes (CNTs) has recently attracted considerable interest because of the issue of biosphere-nanomaterial interactions. The biocompatibility of CNTs is determined by the metal impurities in the CNTs, the size of the CNTs and the CNT dispersion states; in particular, the type of surface modifications on the CNTs affects how they interact with cells and determines their cytotoxicity and cellular uptake. In this study, biocompatible single-walled carbon nanotubes (SWNTs) wrapped with a water-soluble copolymer, poly[2-(dimethylamino)ethyl methacrylate-co-methacrylic acid] (PDM), were prepared. We report that these SWNTs have enhanced water dispersibility and cellular internalization but no significant cytotoxic activity against mouse embryonic fibroblast NIH-3T3 cells.

Carbon nanotubes in the biological interphase: the relevance of noncovalence

With the increasing interest in the biological applications of carbon nanotubes, their interactions in the biological interphase and their general cytotoxicity have become major issues. In spite of their salient properties, major hurdles still exist for their use in biological applications, due to their main characteristics, including their hydrophobic surfaces and tendency to aggregate, as well as their unknown interactions in the cellular interphase. In this Research News, these characteristics of carbon nanotubes, a model nanomaterial, are investigated. Thus, the cytotoxicity of carbon nanotubes, the influence of functionalization, as well as their interactions with different mammalian cell lines are studied. Moreover, suggestions for the improvement of their biocompatibility and the design of biocompatible carbon nanotube-based systems are provided.

Accumulation of Element Ti in Macrophage-like RAW264 Cells Cultured in Medium with 1 ppm Ti and Effects on Cell Viability, SOD Production and TNF-.ALPHA. Secretion

The adverse effect of Ti on body-defense macrophage is not well understood. The aims of this study were twofold: (1) to examine the intracellular accumulation of Ti element; and (2) to measure the cell viability, superoxide dismutase (SOD) production, and TNF-alpha secretion of macrophage-like RAW264 cells cultured for two days in medium with 1 ppm Ti prepared from acidic ICP Ti standard solution. PIXE analysis showed that element Ti was accumulated up to 7.3 ppm in RAW264 cells when cultured in the medium with 1 ppm Ti. Further, RAW264 cells cultured in the medium with 1 ppm Ti exhibited cell viability of about 60%, SOD production of about 180%, and TNF-alpha secretion of about 170% relative to those of control cells cultured in the medium without Ti. It was speculated that phagocytosis of minute Ti-containing complex (mostly TiO2) by macrophage caused oxidative stress and inflammatory reaction, leading to cell proliferation arrest and increased production of SOD and TNF-alpha.

Electrical stimulation of transforming growth factor-beta 1 secretion by human dermal fibroblasts and the U937 human monocytic cell line

The in vitro effects on human dermal fibroblasts and the U937 human monocytic cell line of three phases of electrical microcurrents generated by the ACE Stimulator were investigated. The growth and viability of growing and confluent dermal fibroblasts were not directly influenced by the separate microcurrent phases. One form of microcurrent (designated phase 1) stimulated both dermal fibroblasts and U937 cells to secrete transforming growth factor-beta 1 (TGF-beta 1), which is an important regulator of cell-mediated inflammation and tissue regeneration, but none of the three phases stimulated secretion of the pro-inflammatory cytokine interleukin-6 by U937 cells. The stimulation of TGF-beta 1 secretion in these experiments was not dramatic (a median increase over control levels of 20-30%), although it could be biologically significant.