The interaction of a model protein, bovine serum albumin (BSA) with two different metal oxide nanoparticles, TiO2 (∼22 nm) and SiO2 (∼14 nm), was studied at both physiological and acidic pH. The pH- and nanoparticle-dependent differences in protein structure and protein adsorption were determined using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermogravimetric analysis (TGA). The results indicated that the surface coverage of BSA decreases with decreasing pH on both TiO2 and SiO2 surfaces, and BSA coverage is higher by a factor of ca. 3–10 times more on TiO2 compared to SiO2. The secondary structure of BSA changes upon adsorption to either nanoparticle surface at both pH 7.4 and 2. At acidic pH, BSA appears to completely unfold on TiO2 nanoparticles whereas it assumes an extended conformation on SiO2. These differences highlight for the first time the extent to which the protein corona structure is significantly impacted by protein-nanoparticle interactions which depend on the interplay between pH and specific nanoparticle surface chemistry.
|Number of pages||8|
|Journal||Journal of Colloid and Interface Science|
|State||Published - May 1 2017|
Bibliographical noteFunding Information:
This work was supported by the National Science Foundation – United States (Grant CBET1640936). Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect those of the National Science Foundation. We would like to thank Professor Allan Guymon laboratory at the University of Iowa in the Department of Chemical and Biochemical Engineering for use of the TGA instrument and Professor Michael J. Sailor laboratory at the University of California, San Diego in the Department of Chemistry and Biochemistry for the zeta potential measurements. We also thank Sanjaya Jayalath for characterization data for some of the nanomaterials used in this study. Additional support for Brittany E. Givens was provided by the Alfred P. Sloan Foundation through the University of Iowa Center for Exemplary Mentoring. We also acknowledge helpful discussions with Professor Sarah C. Larsen, Dr. Imali A. Mudunkotuwa and Dr. Sean E. Lehman during the course of this work.
© 2017 Elsevier Inc.
- Protein adsorption
- Surface chemistry
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry