Zetasizer nano zs zen3600 device

Pristine PSNPLs (PP-008-10) and yellow fluorophore-conjugated PSNPLs (y-PSNPLs) (FP-00552-2) were purchased from Spherotech (Chicago, IL, USA). The pristine form of polystyrene (PS) particles was used for all the experiments carried out except for those in which the fluorescent marker was required, such as the visualization and the quantification of PS particles internalization by confocal microscopy and flow cytometry, respectively. PSNPLs used for the assays were characterized using Zetasizer and transmission electron microscopy (TEM) methodologies. To that purpose, the obtained dispersions were diluted to a final concentration of 100 μg/mL in distilled water. The hydrodynamic size and the Z-potential values for PSNPLs and y-PSNPLs dispersions were determined in a Malvern Zetasizer Nano ZS zen3600 device (Malvern, UK). All the parameters for each sample were measured in triplicates. TEM grids were dipped into PSNPLs and y-PSNPLs dispersions and visualized on a JEOL JEM-1400 instrument (JEOL LTD, Tokyo, Japan). To determine the mean size, 100 randomly selected PSNPLs were measured using an Image J software with the Fiji extension.

Both the fluorescent (y-PSNPs) and non-fluorescent polystyrene nanoplastics (PSNPs) used in this study were commercially obtained (Spherotech, Inc., Chicago, IL, USA), having a nominal diameter of about 50 nm. To characterize these nanoplastics, nanoparticle dispersions were prepared at a concentration of 100 μg/mL in distilled water, and DMEM. To measure the average size of the nanoparticles, images were taken using a transmission electron microscopy (TEM) JEOL JEM-1400 instrument (Jeol LTD, Tokyo, Japan). The diameters of 100 randomly selected nanoparticles were measured with the Image J software (National Institutes of Health, Bethesda, MD, USA) and the mean size was calculated with GraphPad Prism 5 Software software (GraphPad Software, Inc., San Diego, CA, USA). Additionally, dynamic light scattering (DLS) and laser Doppler velocimetry (LDV) were used to measure the hydrodynamic size and the Z-potential of particles in water, and in DMEM at the same final concentration, in a Malvern Zetasizer Nano Zs zen3600 device (Malvern, UK).