Monocytes-based in vitro assay for a preliminary biocompatibility assessment of blood-contacting devices

The biological evaluation of biomaterials is currently defined by the ISO-10993 norm in which parts four and five are dedicated to emo-compatibility and cell toxicity, respectively. Our study will provide a novel in vitro experimental approach for the biocompatibility assessment of biomaterials or medical devices using human primary monocytes as cellular model. In these new settings, human monocytes are exposed to a medium containing the extractable compounds derived from materials or devices; subsequently, cell toxicity and pro-inflammatory effects are analysed through MTT assay, flow cytometry and enzyme-linked immunosorbent assay (ELISA) methodologies. These experimental procedures offer the advantage to use a human and primary cell context belonging to the immune system, in order to accurately predict the nature of blood/device interaction occurring during a clinical application. To validate the reliability of this method, we also reported a comparative study between two different membranes showing a different level of biocompatibility. On the bases of these data, it is possible to state that this new experimental model represents a good approach to investigate the effects induced by a biomaterial on cell death and inflammation using human, primary monocytes.