Monday, October 17, 2011

Effects of Cobalt Nanoparticles on Human T Cells In Vitro.

[  Connie's preamble:  I have  spent a number of months looking at the potential genotoxic effects of Chromium on cells in patients with hip implants.  I just noted this article which talks about the potential gentoxic/cytotoxic effects that Cobalt might have  on the patients T cells. This article was released pre publication in the journal.
In genetics, genotoxicity describes a deleterious action on a cell's genetic material affecting its integrity
Cytotoxicity is the quality of being toxic to cells.
 T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. Lymphocytes identify invaders in the body and destroy them.  In this case, we would be targeting Cobalt as an invader in the body which the system would want to wipe out.  If the T lymphocytes are not working properly and are inhibited, problems could arise of various sorts. The function of T cells and B cells is to recognize specific “non-self” antigens, during a process known as antigen presentation. Once they have identified an invader, the cells generate specific responses that are tailored to maximally eliminate specific pathogens or pathogen infected cells. B cells respond to pathogens by producing large quantities of antibodies which then neutralize foreign objects like bacteria and viruses.
These tests were conduced in vitro. that is, they are lab experiments NOT conducted on humans or organisms.]
Biol Trace Elem Res. 2011 Oct 4. [Epub ahead of print]


Department of Orthopedics, The First Affiliated Hospital of Soochow University, Shizi Street, Suzhou, 215006, Jiangsu Province, People's Republic of China.


Limited information is available on the potential risk of degradation products of metal-on-metal bearings in joint arthroplasty. The aim of this study was to investigate the cytotoxicity and genotoxicity of orthopedic-related cobalt nanoparticles on human T cells in vitro. T cells were collected using magnetic CD3 microbeads and exposed to different concentrations of cobalt nanoparticles and cobalt chloride. Cytotoxicity was evaluated by methyl thiazolyl tetrazolium and lactate dehydrogenase release assay. Cobalt nanoparticles dissolution in culture medium was determined by inductively coupled plasma-mass spectrometry. To study the probable mechanism of cobalt nanoparticles effects on T cells, superoxide dismutase, catalase, and glutathione peroxidase level was measured. Cobalt nanoparticles and cobalt ions could inhibit cell viability and enhance lactate dehydrogenase release in a concentration- and time-dependent manner (P < 0.05). The levels of cobalt ion released from cobalt nanoparticles in the culture medium were less than 40% and increased with cobalt nanoparticles concentration. Cobalt nanoparticles could induce primary DNA damage in a concentration-dependent manner, and the DNA damage caused by cobalt nanoparticles was heavier than that caused by cobalt ions. Cobalt nanoparticles exposure could significantly decrease superoxide dismutase, catalase, and glutathione peroxidase activities at subtoxic concentrations (6 μM, <CC(50)). These findings suggested that cobalt nanoparticles could generate potential risks to the T cells of patients suffer from metal-on-metal total hip arthroplasty, and the inhibition of antioxidant capacity may play important role in cobalt nanoparticles effects on T cells

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