The results obtained from exposure studies with the CULTEX RFS module have shown that the interactions between cells and particles are closely linked to the physical and chemical properties of these compounds and have advanced the redesign of the handmade CULTEX glass modules.
Increase of dispersion of stiffness values for cells that were cultured for 1 h as compared to dispersion of stiffness values for cells that were cultured for 24 h suggests that interactions between cells and particles are in their active phase.
Contact was made under gentle stirring, producing random collisions between cells and particles under mild heterogeneous shear stress on the order of 1 to 10 dyne/cm2.
The time span between seeding the cells, particle incubation and CARS measurements lasted no longer than 48h.
Moreover, nucleic acid staining for distinguishing between cells and abiotic particles and the employment of polymer beads for standardization have been found useful in overcoming this limitation [ 16, 17, 24].
Pulmonary damage may be the direct consequence of toxic interaction between quartz particles and cell membranes, or it may be due to silica-induced production of oxidant species by pulmonary phagocytes, that in turn overwhelms pulmonary antioxidant systems and causes lung injury.
It is possible that the F-MWCNTs were preferentially taken up by macrophages due to a relatively lower agglomeration status, allowing more contact between dispersed particles and cells and/or increased uptake via penetration of the cell membrane or other vesicle-mediated processes.
PEG shielding minimizes the non-specific interaction between PVX particles and cells, so few particles were taken up by either cell line (Figs. 7a, 7d).
Walberg's results indicate that, under the conditions tested, drug responses can be detected by light scatter alone, without staining the cells, but, as Walberg points out, in clinical samples, fluorescence measuring is important in order to distinguish between cells and other particles like debris.
