Early Stage Soft Protein Corona Identification on Nanoparticles via Extended Size Exclusion Chromatography

Area of Science:

• Nanotechnology
• Biomaterials Science
• Analytical Chemistry

Background:

• The soft protein corona (SPC) on nanoparticles is poorly understood due to separation challenges.
• Limited knowledge exists on the dynamic structure and composition of SPC.
• Distinguishing SPC from the hard protein corona (HPC) is critical for understanding nanoparticle behavior.

Purpose of the Study:

• To identify and characterize the soft protein corona (SPC) on polystyrene nanoparticles (NPs).
• To investigate the formation and composition of SPC at early time scales (seconds).
• To develop a method for separating SPC-coated NPs from plasma.

Main Methods:

• Utilized extended size exclusion chromatography (SEC) columns (200 mm) for separation.
• Employed transmission electron microscopy (TEM) and dynamic light scattering (DLS) for structural analysis.
• Performed liquid chromatography-mass spectrometry (LC-MS) to determine protein composition.

Main Results:

• Successfully separated SPC-coated NPs from excess plasma using SEC.
• Observed that SPC-coated NPs have a thicker shell than HPC-coated NPs.
• LC-MS revealed lower protein diversity in SPC (59-93 proteins) compared to HPC (152 proteins) within the first 120 seconds.

Conclusions:

• The study successfully identified SPC on nanoparticles at biologically relevant, short time scales.
• SPC formation is a rapid process involving competitive adsorption and displacement of abundant proteins.
• Time-resolved characterization methods are essential for understanding nanoparticle-protein interactions.