Reproductive toxicity in adult male rats following intra-articular injection of cobalt-chromium nanoparticles

Background Recent studies have reported that metallic nanoparticles and ions from cobalt-chromium (CoCr) alloy prostheses had potential adverse effects. However, the biological effects of CoCr nanoparticles on male reproductive function remain unclear. The objective of this study is to investigate the reproductive toxicity in adult male rats following intra-articular injection of cobalt-chromium nanoparticles. Methods CoCr nanoparticles were generated by a spark discharge method. Adult male rats received intra-articular injections of CoCr nanoparticles once a week at a low (20 lg/kg b.w.), medium (100 lg/kg b.w.) or high dose (500 lg/kg b.w.) for 10 consecutive weeks. The control group received intra-articular injections of physiological saline. After the final injection, all rats were held for a 7-day post-exposure period. The effects on male reproductive function were observed, including the coefficient of testicular to body weight, the epididymal sperm parameters, the concentration of metal ions in serum and testis, the activity of antioxidase and the content of lipid peroxide in the testis, and histopathological examination. Results Compared with the control group, intra-articular injection of high dose CoCr nanoparticles could significantly reduce epididymal sperm motility, viability and concentration, increase abnormal sperm rate and levels of Co and Cr ions in serum and in the testis, and induce testicular damage and pathological changes via oxidative stress. Conclusions Intra-articular injection of high dose CoCr nanoparticles from MOM articulation may have potential reproductive toxicity in adult male rats.