A comparison of techniques for size measurement of nanoparticles in cell culture medium

The particle size and particle size distribution of plain and aminated silica nanoparticles was measured in purified water, Tris-HCl buffer and in cell culture medium using dynamic light scattering (DLS), centrifugal liquid sedimentation (CLS), small angle Xray scattering (SAXS), and particle tracking analysis (PTA). The diluted test samples were measured by all methods immediately after dispersion, and after incubation at room temperature for 24 h. The effect of the biological dispersion medium on the sizing results was compared to the uncertainty stated for each method. For the methods based on light scattering like DLS and PTA, the obtained size distributions were significantly altered due to the formation of a protein corona and induced agglomeration effects. With SAXS and CLS, the size of the primary particles was shown to be mostly unaffected. While SAXS offers the excellent precision and SI-traceability if the model fitting is used, CLS provides detailed size distributions from which additional information can be deduced on the aggregation state and the protein corona.JRC.F.6-Reference Material