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 on granulocyte-macrophage colony-forming units.

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

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

1.4 The values stated in SI units are to be regarded as standard. No other units 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 and health practices and determine the applicability of regulatory limitations prior to use.