4.1 This practice is a guideline for a short-term screening test for the evaluation of the tissue response to materials that may be selected for implantation in the human body and should be done in accordance with good laboratory practices. This test may be performed prior to long-term testing (for example, Practice F981) to eliminate unsuitable candidate materials early and to avoid unnecessary animal testing.

4.2 This practice may be used to detect toxic effects of materials in general (see Appendix X1). However, it is particularly suitable for the testing of materials that are intended to have contact with subcutaneous tissues or soft tissues in general. For materials intended to be inserted specifically into muscle tissues, Practice F763 should be considered as a short-term test method.

4.3 The suggested implant specimens are cylindrical. A special grooved type of cylinder may be used (see Fig. X2.1 of Appendix X2) to allow tissue interlocking that could keep the implant in place and minimize tissue irritation through motion at the interface that otherwise could contribute to increased variance of the results. In case ungrooved cylinders are used (see Fig. X1.2 of Appendix X2), probable motion at the implant/tissue interface must be taken into account. Control cylinders should be shaped like the test cylinders.

4.4 The type of surface preparation of the specimens can affect the tissue reaction; therefore the preparation procedure should be noted in the report. The test may be used to compare the effect of different surface structures or conditions of the same material or to assess the effect of various treatments of modifications of a material.

Note 1: If this method is used for material research, testing for endotoxin prior to implantation should be considered.

1.1 This practice covers a short-term testing method to screen the subcutaneous tissue reaction to implant candidate materials in small laboratory animals. The material may be dense or porous. This method may not work for absorbable materials, depending on the absorption kinetics. The tissue reactions will be evaluated in comparison to those evoked by control materials that are accepted as clinical implant materials.

1.2 This practice, along with other appropriate biological tests (including other ASTM test methods), may be used to assess the biocompatibility of candidate materials for use in the fabrication of devices for clinical application. It may be also applied to evaluate the effect of special surface textures and preparations of known materials.

1.3 This practice does not provide a comprehensive assessment of the systemic toxicity, carcinogenicity, teratogenicity, or mutagenicity of the material. Additional information may be needed on the material in its final finished form, such as implantation assessment at the clinically relevant location.

1.4 The values stated in SI units, including units officially accepted for use with SI, are to be regarded as standard. No other systems of measurement are included in this standard.

1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.