Characterization of Protein Corona on Gold Nanoparticles Via SDS-PAGE

Nanoparticulate drug carriers encounter a vast number of biological compounds when traveling through the human body. The majority of these compounds are proteins commonly found in biological fluids like blood and lung fluids. The proteins in these biological fluids adhere to the exterior of the nanoparticle and mask the particle’s surface chemistry. This can be detrimental to therapies that rely on their surface chemistry to illicit a desired response in areas with high protein concentration, like the lower lungs. Zwitterionic polymer coatings can reduce the number of proteins binding to the nanoparticles, thus improving drug potency. In the current study, bare gold and polymer coated gold nanoparticles were introduced to protein-rich human serum and bronchoalveolar lavage fluid (BALF). The proteins that adhered the nanoparticle surfaces were then characterized with 1D SDS-PAGE, to separate the proteins based on size, followed by mass spectrometry, to verify protein composition in the SDS-PAGE bands. We have observed a substantial decrease in the intensity of protein bands between the polymer coating and the raw nanoparticles. The intensity of the bands is directly correlated to the number of proteins binding to the particles’ surface. Entire bands that were observed on the bare nanoparticles had disappeared on the polymer coated trials. Future studies will determine the impact the polymer size and coating density on protein adsorption.