  Protein corona formation and nanoparticle aggregation have been heavily
discussed over the last years since the lack of fine-mapping of these two
combined effects has hindered the targeted delivery evolution and the
personalized nanomedicine development. We present a multi-technique approach
that combines Dynamic Light and Small-Angle X-ray Scattering techniques with
cryo-Transmission Electron Microscopy in a given fashion that efficiently
distinguishes protein corona from aggregates formation. This methodology was
tested using 25-nm model silica nanoparticles incubated with either model
proteins or biologically relevant proteomes (such as fetal bovine serum and
human plasma) in buffers of low and high ionic strengths to precisely tune
particle-to-protein interactions. In this work, we were able to differentiate
protein corona, small aggregates formation, and massive aggregation, as well as
obtain fractal information of the aggregates reliably and straightforwardly.
The strategy presented here can be expanded to other particle-to-protein
mixtures and might be employed as a quality control platform for samples that
undergo biological tests.
