YY/T 0870.3-2019Test for genotoxicity of medical devices - Part 3: TK gene mutation test using mouse lymphoma cells (English PDF)

Foreword

YY/T 0870 "Medical Toxicity Test for Medical Devices" consists of the following components.

--- Part 1. Bacterial back mutation test;

--- Part 2. In vitro mammalian cell chromosome aberration test;

--- Part 3. TK gene mutation test using mouse lymphoma cells;

--- Part 4. Mammalian bone marrow erythrocyte micronucleus test;

--- Part 5. Mammalian bone marrow chromosome aberration test. This part is the third part of YY/T 0870.

This part is drafted according to the rules given in GB/T 1.1-2009.

This part replaces YY/T 0870.3-2013 "Medical equipment genotoxicity test - Part 3. Body with mouse lymphoma cells The foreign mammalian gene mutation test, compared with YY/T 0870.3-2013, except for editorial changes, the main technical changes are as follows.

--- Standard name modified to "Determination of genotoxicity of medical devices - Part 3. TK gene mutations using mouse lymphoma cells test";

--- Added terminology. cloning efficiency (see 3.1); chromosomal cleavage agents (see 3.2); frameshift mutants (see 3.4); mitotic recombination (see 3.5); mutation (see 3.6); phenotypic expression time (see 3.8); suspension growth (see 3.10); relative suspension growth rate (see 3.11);

For total growth (see 3.12); S9 liver homogenate (see 3.13); S9 mixture (see 3.14); untreated control (see 3.15);

--- Added a note to S9 (see Chapter 5);

--- Revised the relevant requirements for cell lines (see 6.1);

--- Revised the relevant steps for spontaneous mutational clearance of cells (see 6.2);

--- Revised the relevant requirements for mycoplasma contamination detection (see 6.3);

--- Revised the relevant requirements for karyotype stability testing (see 6.4);

--- Increased the selection principle of positive controls (see 9.2);

--- Added "untreated control" (see 9.3);

--- Added an overview of the pre-experiment (see 10.1.1);

---Modified the relevant steps of "contact processing" (see 10.1.2);

--- Modified "0 days of plating efficiency (PE0 plate)", changing the plate culture time to 10d ~ 12d (see 10.1.3);

--- Revised the plate culture time, changed to 10d ~ 12d (see 10.2.3.3);

--- Increased the "relative suspension growth rate" (RSG) (see 11.3);

--- Added "Related Total Growth (RTG)" (see 11.4);

--- Removed the "type (4) small colony mutation rate" (see 11.4);

--- Increased "laboratory capabilities" (see 12);

--- Added "historical comparison data" (see 13);

--- Added "negative criteria" (see 14.1);

--- Added "positive judgment criteria" (see 14.2);

--- Added "result evaluation" (see 15);

--- Added background knowledge (see Appendix A).

Introduction

The test methods for detecting potentially genotoxic substances given in GB/T 16886.3 are issued by the Organisation for Economic Co-operation and Development (OECD).

The methods specified in the Chemical Testing Guide, but these methods are developed for the characteristics of the chemical, and no detailed tests are given.

The steps are therefore not suitable for direct use in the detection of medical devices/materials. This part of YY/T 0870 refers to the basic original OECD test method.

Then, according to the characteristics of the medical device/material, the test method is appropriately modified, and detailed test procedures are specified, which can be used as Supplementary method standard for genotoxicity test in GB/T 16886.3.

This part of YY/T 0870 refers to OECD490 (2016) "In vitro mammalian cell gene mutation test using TK gene" And combined with the characteristics of the medical device/material itself, that is, the mouse is induced by the medical device/material with and without the metabolic activation system.

The positive mutation of the lymphoma cell (L5178YTK/-3.7.C) gene was used to evaluate the potential mutagenicity of the test sample.

In this section, cells are selected based on whether the growth ability and the spontaneous mutation rate in the culture solution are stable. In vitro tests are usually required To activate the system with exogenous metabolism. However, exogenous metabolic activation systems do not fully mimic metabolic conditions in mammals. pH and Changes in osmotic pressure or higher cytotoxicity of the test sample can lead to false positive results, making the test results incapable of reacting in vivo Change the real situation. See Appendix A for background information on the TK gene mutation test in the OECD. Medical device genotoxicity test - Part 3. TK gene mutation test in lymphoma cells

1 Scope

This section of YY/T 0870 specifies the use of the mouse lymphoma cell line (L5178YTK /-3.7.2C) for medical devices/materials. Method for in vitro mammalian cell gene mutation assay.

This section applies to the TK gene mutation test using the mouse lymphoma cell line (L5178YTK /-3.7.2C) using the microplate method.

A method of assessing cytotoxicity using both relative survival (RS) and relative total growth (RTG) indicators.

Note 1. In vitro mammalian cell gene mutation test of oral materials can be found in YY/T 0127.17.

Note 2. In vitro mammalian cell gene mutation testing of nanomaterials may require specific revisions to the methods in this section, but this section does not give description.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 16886.1 Biological evaluation of medical devices - Part 1. Evaluation and testing in the process of risk management

GB/T 16886.3 Biological evaluation of medical devices - Part 3. Tests for genotoxicity, carcinogenicity and reproductive toxicity

GB/T 16886.12 Biological evaluation of medical devices - Part 12. Sample preparation and reference materials

3 Terms and definitions

The following terms and definitions as defined in GB/T 16886.1, GB/T 16886.3 and GB/T 16886.12 apply to this document.