First Steps To Nanomedicine: Assessing Interactions Between Polystyrene Nanoparticles And Albumin Proteins

Nanoparticles (NPs) have gained traction for various biomedical applications, however, when injected in complex biological mediums such as blood, NPs accrue a protein “coat”, affording them a new identity in vivo. To ensure NPs can be used to their full potential, a basic understanding of protein-NP interactions must be  established. This research aims to answer: What are the kinetics and thermodynamics between bovine serum albumin (BSA) and fluorescent polystyrene NPs (FluoSpheres, FS), and how do changes in size affect these parameters?

Interactions between FS and BSA will be assessed using two-photon excitation fluorescence crosscorrelation spectroscopy (TPE-FCCS). This technique allows for direct, in situ measurement of fluorescently-labeled species and their interactions. Results suggest low binding ratios (~ 40 proteins and ~ 770 proteins per 100 and 200 nm sphere, respectively) and on-rates on the order of 104 M-1 s-1, which challenges the current understanding of the formation of a protein corona.