OMPG tests skin irritation without animal testing

Dr. Thomas Dauben, head of the OMPG biology laboratory in Rudolstadt, during a cytotoxicity test. The different coloration on the microtiter plate indicates whether the cells are doing well. If the color is rather pale, their vitality is restricted by harmful substances. (Image rights: OMPG / Steffen Beikirch)

At OMPG in Rudolstadt, you can also feel that a lot is happening in this area. The test laboratory offers biological testing of medical devices and is accredited for this by the German Accreditation Body (DAkkS) and the Central Authority of the Federal States for Health Protection with regard to Medicinal Products and Medical Devices (ZLG). “These tests are used to assess the biocompatibility of medical devices and are a prerequisite for their approval,” says Laboratory Manager Dr. Thomas Dauben. The MDR regulation requires this proof for all materials with which patients, medical staff or other users may come into contact.

Three test methods are used to assess biocompatibility: testing for cytotoxicity, skin irritation and sensitization. “Manufacturers usually request all three tests from us as a package,” reports Dauben. However, OMPG customers most frequently order the cytotoxicity test in accordance with DIN EN ISO 10993-5. “This is the first and most important test in the biocompatibility assessment of medical devices. Only if there are signs of problems here is it worth going into more depth with the other two significantly more complex tests,” says the laboratory manager.

When testing for cytotoxicity, an extraction medium is added to the medical device to dissolve out potentially harmful substances. The extract is applied to living cells in various dilutions. After a certain incubation period under detailed conditions, the cells are then examined by means of a biochemical reaction to determine whether their growth or vitality has been restricted by harmful substances.

While this test has always been cell-based, the two further tests are usually carried out in conjunction with animal experiments. Not so at the OMPG: the Rudolstadt laboratory uses a method with three-dimensional human skin models to test for skin irritation. The OMPG is also currently establishing animal-free methods for testing for sensitization through allergenic potential, which should be available soon.

Meanwhile, an external round robin test has now been offered for the first time for the cytotoxicity test, in which the OMPG participated. “In the past, laboratories had to make their own efforts to carry out comparative tests with other service providers,” says Dauben. This is why the round robin test organized for the first time by the Johner Institute (Constance) with 18 laboratories, an external task and an independent external assessment is to be rated significantly higher. “The OMPG successfully passed the round robin test. This result is very important for our quality assurance and confirms that our processes are stable and guarantee reliable, reproducible results,” says Dauben.