Hospital infections represent the fourth most frequently occurring disease of the modern world and cause the most frequent complications in hospital treatment. Transfer of bacteria or bacterial biofilms is a problem also in other environments such as public transport or food packaging. For the destruction of existing bacteria, various biocidal preparations are often used which may contain various organic compounds such as trichlosan antibiotics. The use of these compounds has undesirable side effects like for example increasing antibiotic resistance of bacteria. It has been shown that ions and nanoparticles of silver and copper except anti-bacterial activity have toxic effects on human cells. Recently, it has been shown that the compounds of the molybdenum (Mo) and tungsten (W) have extremely antibacterial properties, and the efficacy of antibacterial activity of their trioxide has been demonstrated on various bacterial cultures.

Molybdenum and tungsten nanoparticles synthesized at the Jožef Stefan Institute possess a unique form and degree of anisotropy, and their antibacterial activity is confirmed in the previous study (unpublished results). In order to use nanomaterials for medical purposes it is necessary to demonstrate that once in contact with live tissue they do not cause tissue damage or allergic reaction, ie they do not induce an inflammatory response. Accordingly, it is necessary to determine the cytotoxicity of molybdenum and tungsten nanoparticles in human cells. Within this project we aim to investigate the biocompatibility of molybdenum and tungsten nanoparticles in human cells, ie examine their cytotoxicity and potentials to stimulate inflammatory response in human cells.