3. BIOLOGICAL / TOXICOLOGICAL ENDPOINTS
Identification of biological effects after exposure
BIOLOGICAL/TOXICOLOGICAL ENDPOINTS
Identification of biological effects after exposure
Medical devices often come into direct contact with human body tissue or fluids. It is important to check that the material of the device does not cause harmful reactions such as inflammation, allergies or tissue damage.
For the approval of medical devices and to ensure that the products are safe for human use, biological tests are carried out in addition to the physical/chemical tests. These tests may be decisive not only to confirm the biocompatibility of the individual extractable substances identified, but also to investigate the effect of the extracts as complex mixtures under clinical conditions and thus minimize potential health risks.
WHAT ARE THE BIOLOGICAL ENDPOINTS FOR ASSESSING BIOCOMPATIBILITY?
Cytotoxicity – ISO 10993-5
Cytotoxicity tests determine the general degree of toxicity of medical devices or their material, i.e. the potential for non-specific cell damage, by means of an elution test or agarose overlay test in cell cultures. A cytotoxicity test is a comparatively inexpensive and very sensitive method of determining the toxic effect of medical devices.
Genotoxicity – ISO 10993-3 and FDA
Genotoxicity tests are used to detect toxins that can interact with and possibly modify the genetic material of cells. This is to ensure that the substances do not cause genetic changes that can lead to cancer or other serious diseases.
Hemocompatibility – ISO 10993-4 and ASTM
Hemocompatibility tests use hematology and thrombosis tests to evaluate the effects of medical devices in contact with human blood and blood components. Devices that come into contact with blood (e.g. catheters or heart valves) must be tested to ensure that they do not cause blood clots or hemolysis.
Irritation – ISO 10993-23
Skin irritation tests assess medical devices for their potential skin damaging/irritating effects. For this purpose, skin and eye reaction tests, intracutaneous reaction tests and in vitro tests for skin irritation are performed.
Sensitization – ISO 10993-10
Sensitization tests are performed to assess possible immune reactions using in vivo and in vitro test methods. The extent to which the products can trigger allergic reactions is investigated.
Systemic effects of potential toxicity and pyrogenicity – ISO 10993-11 and ASTM
These are tests for acute to chronic systemic toxicity from substances that may be harmful to the body. Pyrogenicity tests prove medical devices for fever-causing substances, so-called pyrogens, which affects patients coming into contact with the medical device.
Testing for implantation effects – ISO 10993-6
These tests assess histologically and pathologically how medical devices affect the surrounding living tissue. The aim is to ensure that there are no negative effects on the surrounding tissue, such as scarring or rejection reactions.
There are numerous other testing methods and biological endpoints. All of these tests are part of a comprehensive risk management process and are often carried out in accordance with international standards such as ISO 10993. Ultimately, they serve to protect and ensure the safety of patients and confirm the reliability and effectiveness of medical devices.
