Ionic cobalt but not metal particles induces ROS generation in immune cells in vitro

Abstract

Total joint replacement is one of the most successful procedures in orthopedic surgery today. However, metal implant materials undergo wear and corrosion processes. Generated particles and ions can cause a variety of cellular reactions. Cobaltcontaining alloys are used frequently in implant materials. Some studies suggest that cobalt exhibits potential cytotoxic effects, for example, via generation of reactive oxygen species (ROS). To further elucidate the effects of cobalt on human cells, we determined cell viability and cytosolic and mitochondrial superoxide formation after incubation of either ions or particles with different cells. MM-6 and Jurkat cell lines were treated for 24, 48 and 72 h with either CoCrMo particles or cobalt ions (supplied as CoCl 2 ). A total of 24 h exposure of both forms of cobalt did not induce cell death using terminal deoxynucleotidyl transferase (TUNEL) and trypan blue assay. Interestingly, the formation of superoxide (O 2 . − ) is evoked mainly by ionic CoCl 2 but not cobalt particles. Cobalt alloy particles are likely to even suppress O 2 .− formation in mitochondria in both used cell lines. Furthermore, we did not observe any effect of cobalt particles on O 2 .− formation in peripheral blood mononuclear cells (PBMCs) from healthy donors. We also found that the O 2 − formation by CoCl 2 within mitochondria is a generalized effect for all cell types used, while the formation of superoxide in cytosolic compartment is cell-type dependent. In summary, our data suggest that cobalt ions specifically induce the formation of O 2 .−, whereas the cobalt particles were better tolerated.

Biological Reactions to Metal Particles and Ions in the Synovial Layer of Mice

“…However, in contrast with the inflammatory reaction results in our murine model, some in vitro studies have shown different results. Chamaon et al indicated that the treatment of a human monocytic cell line with ionic cobalt led to a decrease in metabolic activity [Water Soluble Tetrazolium-1(WST-1) assay], while CoCrMo particles had no effect [47]. They explained that the rather large abrasive particles (from 200 nm to several micrometers) used in their study might have resulted in the relatively low impact of CoCrMo particles [47].…”

“…Chamaon et al indicated that the treatment of a human monocytic cell line with ionic cobalt led to a decrease in metabolic activity [Water Soluble Tetrazolium-1(WST-1) assay], while CoCrMo particles had no effect [47]. They explained that the rather large abrasive particles (from 200 nm to several micrometers) used in their study might have resulted in the relatively low impact of CoCrMo particles [47]. Because particle size is considered a critical parameter that influences the biological reactions to wear particles, the majority of MoM-produced particles are usually from 40 to 60 nm [2,48].…”

The gut microbiota may be a novel pathogenic mechanism in loosening of orthopedic implants in rats

“…The proposed model of bi-directional, cyclic crosstalk between the gut microbiome and implant microenvironment. Arthrofibrosis, as discussed in the text, may be a contributing factor stress, 95 and contribute directly to alterations in the gut microbiome. 96,97 Cobalt ions are known to be absorbed by the human small intestine when ingested.…”

Modern aspects of regulatory, pathophysiological and toxic effects of cobalt ions during oral intake in the human body

“…The authors highlighted that toxic effects of cobalt dichloride depended on a dose and a time period during which cells were exposed to a medium containing heavy metal ions. It was reported that cobalt dichloride was able to induce the formation of a superoxide anion in the mitochondria of various human cells [27].…”