title: Alterations in nanoparticle protein corona by biological surfactants: impact of bile salts on β-lactoglobulin-coated gold nanoparticles.
abstract: The impact of biological surfactants (bile salts) on the protein (β-lactoglobulin) corona surrounding gold nanoparticles (200 nm) was studied using a variety of analytical techniques at pH 7: dynamic light scattering (DLS); particle electrophoresis (ζ-potential); UV-visible (UV) spectroscopy; transmission electron microscopy (TEM); and surface-enhanced Raman scattering (SERS). The bile salts adsorbed to the protein-coated nanoparticle surfaces and altered their interfacial composition, charge, and structure. SERS spectra of protein-coated nanoparticles after bile salt addition contained bands from both protein and bile salts, indicating that the protein was not fully displaced by the bile salts. UV, DLS and TEM techniques also indicated that the protein coating was not fully displaced from the nanoparticle surfaces. The impact of bile salts could be described by an orogenic mechanism: mixed interfaces were formed that consisted of islands of aggregated proteins surrounded by a sea of bile salts. This knowledge is useful for understanding the interactions of bile salts with protein-coated colloidal particles, which may be important for controlling the fate of colloidal delivery systems in the human gastrointestinal tract, or the gastrointestinal fate of ingested inorganic nanoparticles.
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA; Department of Biotechnology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand; Center of Excellence on Agricultural Biotechnology (AG-BIO/PERDO-CHE), Bangkok 10900, Thailand.
authors.forename: Thunnalin
authors.initials: T
authors.lastname: Winuprasith
authors.affiliation: Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA 1003, United States.
authors.forename: Sirinya
authors.initials: S
authors.lastname: Chantarak
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand; Center of Excellence on Agricultural Biotechnology (AG-BIO/PERDO-CHE), Bangkok 10900, Thailand.
authors.forename: Manop
authors.initials: M
authors.lastname: Suphantharika
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Lili
authors.initials: L
authors.lastname: He
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA. Electronic address: mcclements@foodsci.umass.edu.
authors.forename: David Julian
authors.initials: DJ
authors.lastname: McClements
mesh_terms: D001647:Bile Acids and Salts / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007782:Lactoglobulins / Q000737:chemistry*; D053768:Metal Nanoparticles; D053758:Nanoparticles; D011506:Proteins / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D001647:Bile Acids and Salts; D007782:Lactoglobulins; D011506:Proteins; D013501:Surface-Active Agents; D006046:Gold
keywords: Bile salts; Gold nanoparticles; Orogenic displacement; Protein corona; Surface-enhanced Raman spectroscopy; β-Lactoglobulin