ASTM E3238-20

5.1 This test method will assess whether the test nanoparticulate material has chemoattractant activity.

5.2 This test method will provide a rapid and quantitative measure of the ability of nanoparticulate material to recruit immune cells.

5.3 Recruitment of immune cells by chemotaxis plays an important part in all phases of both humoral and cell-mediated immune responses.

5.4 Testing the capacity of a nanoparticulate material to recruit immune cells in vitro helps in predicting the influence of such material on the immune cell response.

1.1 This test method provides a protocol for rapid and quantitative measurement of the chemoattractant capacity of a nanoparticulate material (nanoparticles and their aggregates and agglomerates).

1.2 Immune cells recruitment (by chemotaxis) plays a central role in the immune system function especially in the inflammatory process.

1.3 This test method uses an in vitro model. In this model, peripheral blood human acute promyelocytic leukemia cells HL-60 are separated from control chemoattractant or test nanoparticulate material by a 3-µm pore size filter; the cell migration through the filter is monitored and quantified using the fluorescent dye calcein AM (Figs. 1 and 2).