【国外标准】 Standard Test Method for Agar Diffusion Cell Culture Screening for Cytotoxicity

4.1 This test method is useful for assessing the cytotoxic potential of new materials and formulations and as part of a quality control program for established medical devices and components.4.2 This test method assumes that assessment of cytotoxicity provides useful information to aid in predicting the potential clinical applications in humans. Cell culture methods have shown good correlation with animal assays and are frequently more sensitive to cytotoxic agents.4.3 This cell culture test method is suitable for incorporation into specifications and standards for materials to be used in the construction of medical devices that are to be implanted into the human body or placed in contact with tissue fluids or blood on a long-term basis.4.4 Some biomaterials with a history of safe clinical use in medical devices are cytotoxic. This test method does not imply that all biomaterials must pass this assay to be considered safe for clinical use (Practice F748).1.1 This test method is appropriate for materials in a variety of shapes and for materials that are not necessarily sterile. This test method would be appropriate in situations in which the amount of material is limited. For example, small devices or powders could be placed on the agar and the presence of a zone of inhibition of cell growth could be examined.1.1.1 This test method is not appropriate for leachables that do not diffuse through agar or agarose.1.1.2 While the agar layer can act as a cushion to protect the cells from the specimen, there may be materials that are sufficiently heavy to compress the agar and prevent diffusion or to cause mechanical damage to the cells. This test method would not be appropriate for these materials.1.2 The L-929 cell line was chosen because it has a significant history of use in assays of this type. This is not intended to imply that its use is preferred, only that the L-929 is an established cell line, well characterized and readily available, that has demonstrated reproducible results in several laboratories.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.