ISO10993, or biocompatibility, refers to the compatibility between medical materials and the patient's tissues and physiological systems. The success of medical materials in clinical and safe use is mainly due to their good biocompatibility. Often, some medical materials release toxic substances during use, resulting in incompatibility with patients. For the purpose of monitoring biocompatibility, the use of medical materials and their extracts is typically simulated under worst-case conditions to ensure safety under normal conditions of use. In ISO 10993, Parts 1 to 20 specify a series of mandatory standards to evaluate the biocompatibility of medical materials. The criterion of the fifth part is to study the cytotoxicity of medical material extracts on established cell lines (in vitro studies). In vitro studies are generally less expensive and easier to perform in some areas where experimentation with animals is opposed.

  ISO10993 test items and methods

  Cell culture experiments are used in biocompatibility studies of medical materials. Generally, there are three approaches to study the cytotoxicity of medical materials.

   The first method is the direct contact method, which is suitable for low density materials such as contact lenses. The test material is placed directly on the cell line and then heated at the appropriate temperature. During the heating process, some soluble chemicals diffuse into the medium and come into direct contact with the cells. The material can be judged to be cytotoxic if the cell lines surrounding the material are deformed, degenerated and decomposed.

   The second method is the agar diffusion method, which is suitable for high-density materials such as synthetic rubber stoppers. Cover the cultured cell line with a piece of nutrient-supplemented agar and place the test material on the agar layer. The dissolution chemicals in the material diffuse into the agar and come into contact with the cells. A material can be judged to be cytotoxic if the cell lines surrounding or beneath the material appear deformed, degenerated and decomposed.

   The third method is the MEM elution method, which is used to judge the cytotoxicity of the test material extracts. Generally, the actual use state or the worst case is simulated, and different extraction agents and conditions are used for extraction. The extract is then transferred to the cell layer and heated, and the cells are observed microscopically for deformity, degeneration and disintegration.

  The above three methods can qualitatively analyze the cytotoxicity of medical materials. If quantitative analysis is to be done, additional tests such as cell death, inhibition of cell growth, cell proliferation or colony formation are required.

   There are many items for biocompatibility testing, and there are usually three items that are most commonly tested:

  1. Cytotoxicity test: Biological evaluation of medical devices Part 5: In vitro cytotoxicity test GB/T 16886.5-2003/ISO 10993-5-1999

  2. Skin irritation test: Biological evaluation of medical devices-Part 10: Test for irritation and delayed type hypersensitivity GB/T 16886.10-2005/ISO 10993-10:2002

  3. Sensitization test: Biological evaluation of medical devices-Part 10: Test for irritation and delayed type hypersensitivity GB/T 16886.10-2005/ISO 10993-10:2002

   With the continuous development of the global cosmetics and daily chemical products industry, consumers are increasingly concerned about the safety of cosmetic and daily chemical products, and the requirements have become more and more stringent. In 2012, the General Administration of Quality Supervision, Inspection and Quarantine reported that there were as many as 332 batches of cosmetic and daily chemical products that were not qualified by the entry-exit inspection and quarantine department in a certain month. At the same time, the increasing international environmental protection voice is constantly exerting pressure on related companies. The development trend of cosmetic and daily chemical products must be green, environmentally friendly and biodegradable products to ensure product quality and environmental requirements.

  Material Biodegradability (Fungi and Bacteria) Biodergradability and disintegration

  GB/T 19275-2003 Evaluation of the potential biodegradation and disintegration ability of materials under the action of specific microorganisms (mainly tested by fungi and bacteria)