To assess the health and safety risks linked with the skin contact with medical devices, Centexbel examines their toxic effect on the skin (cytotoxicity, irritation, sensitivity,…) according to ISO 10993-5 “Biological evaluation of medical devices – part 5 - cytotoxicity : in vitro methods”.
Mammal cells are brought into contact with a material extract. The cell toxicity is then determined by measuring the viability of the cells by means of a MTT-test. This test measures the redox potential of the active living cells through a colorimetric reaction (reduction of MTT to coloured Formosan). The intensity of the measured colourisation therefore corresponds with the number of living cells present during the test and with their metabolic activity.
The results are expressed as a percentage of 100% viability (check). If the average cell viability of the tested samples is less than 70%, the textile extract is considered cytotoxic.