B. Sensitization
There are two types of sensitization tests that are generally submitted in support of IDE and marketing applications: the Guinea Pig Maximization Test and the Local Lymph Node Assay. In addition, the Buehler method can be used for topical devices only (i.e., those in contact with skin), per ISO 10993-10.
Guinea Pig Maximization Test (GPMT)
For this test, male and/or female healthy young adult animals are used. If female animals are used, the animals should be nulliparous and non-pregnant, as pregnancy reduces the ability of a female animal to detect a sensitization response.
Assays with positive controls using the same source and strain of animals only should be performed regularly (at least once every six months, or if longer, …show more content…
Local Lymph Node Assay (LLNA)
The use of LLNA tests is for medical devices on a case-by-case basis for medical device extract/residuals that are composed of chemical mixtures. LLNA tests may be appropriate in the following circumstances:
• The LLNA can be used for testing metal compounds (with the exception of nickel and nickel-containing metals) unless there are unique physicochemical properties associated with these materials (e.g., nanomaterials) that may interfere with the ability of the LLNA to detect sensitizing materials.
• The LLNA can be used for testing device materials in aqueous solutions unless there are unique physicochemical properties associated with these materials (e.g., nanomaterials) that may interfere with the ability of the LLNA to detect sensitizing chemicals. When testing device materials in aqueous solutions, it is essential to use an appropriate vehicle to maintain the test extract in contact with the skin (e.g., 1% Pluronic L92) so that adequate exposure can be achieved, as demonstrated by positive control …show more content…
For borderline positive responses between an SI of 1.8 and 2.5 there is a potential for false positive results that could limit the usefulness of this type of LLNA test. In addition, the LLNA: DA is not appropriate for testing device materials that affect ATP levels (e.g., chemicals that function as ATP inhibitors) or those that affect the accurate measurement of intracellular ATP (e.g., presence of ATP degrading enzymes, presence of extracellular ATP in the lymph
There are two types of sensitization tests that are generally submitted in support of IDE and marketing applications: the Guinea Pig Maximization Test and the Local Lymph Node Assay. In addition, the Buehler method can be used for topical devices only (i.e., those in contact with skin), per ISO 10993-10.
Guinea Pig Maximization Test (GPMT)
For this test, male and/or female healthy young adult animals are used. If female animals are used, the animals should be nulliparous and non-pregnant, as pregnancy reduces the ability of a female animal to detect a sensitization response.
Assays with positive controls using the same source and strain of animals only should be performed regularly (at least once every six months, or if longer, …show more content…
Local Lymph Node Assay (LLNA)
The use of LLNA tests is for medical devices on a case-by-case basis for medical device extract/residuals that are composed of chemical mixtures. LLNA tests may be appropriate in the following circumstances:
• The LLNA can be used for testing metal compounds (with the exception of nickel and nickel-containing metals) unless there are unique physicochemical properties associated with these materials (e.g., nanomaterials) that may interfere with the ability of the LLNA to detect sensitizing materials.
• The LLNA can be used for testing device materials in aqueous solutions unless there are unique physicochemical properties associated with these materials (e.g., nanomaterials) that may interfere with the ability of the LLNA to detect sensitizing chemicals. When testing device materials in aqueous solutions, it is essential to use an appropriate vehicle to maintain the test extract in contact with the skin (e.g., 1% Pluronic L92) so that adequate exposure can be achieved, as demonstrated by positive control …show more content…
For borderline positive responses between an SI of 1.8 and 2.5 there is a potential for false positive results that could limit the usefulness of this type of LLNA test. In addition, the LLNA: DA is not appropriate for testing device materials that affect ATP levels (e.g., chemicals that function as ATP inhibitors) or those that affect the accurate measurement of intracellular ATP (e.g., presence of ATP degrading enzymes, presence of extracellular ATP in the lymph