5.1 Stem cells of hematopoietic origin are pluripotential and may be particularly sensitive to the effects of stimulation by nanoparticulate materials.

5.2 The effect of particles on macrophage responses has an extensive history and can be assessed by Practice F1903. The test method described here will assess the effect on stem cells which can be progenitor cells to the macrophage line.

1.1 This test method provides a protocol for quantitative analysis of the effect of nanoparticulate materials in physiologic solution (isotonic, pH 7.2 ± 0.2) on granulocyte-macrophage colony-forming units (CFU-GM).

1.2 CFU-GM reflects the number of viable bone marrow cells which differentiate into granulocytes and macrophages. A decrease in CFU-GM count is indicative of a test substance’s toxicity to bone marrow and is commonly used for the identification of drug products with myelosuppressive properties, a form of immunosuppression.

1.3 This test method employs murine bone marrow hematopoietic stem cells which proliferate and differentiate to form discrete cell clusters or colonies which are counted.

1.4 This test method is part of the in vitro preclinical characterization cascade for nanoparticulate materials for systemic administration in medical applications.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 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.

1.7 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.