From nanotechnology to nanogenotoxicology: genotoxic effect of cobalt-chromium nanoparticles

Nanotechnology is a multi-disciplinary technology that processes the materials that can be measured with nanometer-level and combines many research field or discipline. Nanomaterials (NMs) are widely used in the fields of science, technology, communication, electronics, industry, pharmacy, medicine, environment, consumer products and military. Until recently little has been known about whether or not nanomaterials have the toxic or hazardous effects on human health and the environment. However, several studies have indicated that exposure to some nanomaterials, e.g. nanoparticles, can cause some adverse effects in humans and animals. Over the last years the number of publications focusing on nanotoxicology has gained momentum, but, there is still a gap about the genotoxicity of nanomaterials.Metal nanoparticles and their alloys with excellent mechanical properties are the materials which can be easily adapted to the mechanical conditions of the musculoskeletal system. Cobalt-chromium alloys are widely used in orthopedic applications as joint prosthesis and bone regeneration material, fillings and dental implants in jaw surgery, and in cardiovascular surgery, especially stent applications. Studies about cytotoxicity and genotoxicity of metal nanoparticles on human indicate that some metal nanoparticles have cytotoxic and genotoxic effects and they may be hazardous for humans. However, a few studies have been reported concerning the genotoxic effects of cobalt-chromium nanoparticles. The data from these studies indicate that cobalt-chromium nanoparticles have cytotoxic and genotoxic effects. It has been stated that the wear debris from implants cause DNA and chromosome damage in patients with cobalt-chromium replacements. It was also found that the risk of urinary cancers such as bladder, ureter, kidney and prostate in patients after hip replacement than among the wider population.Because there are very little biocompatibility and toxicity tests on the long-term effects of nanoparticles and limited number of research focused on nanogenotoxicity, the effect mechanisms of nanoparticles on cells especially genetic material are not yet elucidated in detail. For this reason the well designed experiments including cell-cycle and DNA repair are required to understand the epigenetic effects of nanoparticles and mechanisms of nanoparticle-induced genotoxic events. Thus we may have information that will allow making the informed designs, ensuring biocompatibility of nanomaterials and minimising their adverse effects for health in the future