title: Insights on the mechanism of formation of protein microspheres in a biphasic system.
abstract: Microspheres of bovine serum albumin (BSA) and silk fibroin are produced by applying ultrasound in a biphasic system consisting of an aqueous protein solution and an organic solvent. The protein microspheres are dispersed in an aqueous media where the protein remains at the interface covering the organic solvent. This only occurs when high shear forces are applied that induce changes to force the protein to the interface. Fourier transform infrared results indicate a large increase in the content of the β-sheet during the formation of silk fibroin microspheres. Molecular dynamics simulations show a clear adaption on the 3D structure of BSA when stabilized at the interface, without major changes in secondary structure. Further studies demonstrate that high water content, oil solvents, and larger peptides with separated and clear hydrophobic and hydrophilic areas lead to more stable and smaller spheres. This is the first time that these results are presented. We also present herein the rationale to produce tailored protein microspheres with a controlled size, controlled charge, and increased stability.
authors.affiliation: Department of Textile Engineering, University of Minho, Campus de Azurém, 4800-058, Guimarães, Portugal.
authors.forename: Raquel
authors.initials: R
authors.lastname: Silva
authors.forename: Helena
authors.initials: H
authors.lastname: Ferreira
authors.forename: Nuno G
authors.initials: NG
authors.lastname: Azoia
authors.forename: Ulyana
authors.initials: U
authors.lastname: Shimanovich
authors.forename: Giuliano
authors.initials: G
authors.lastname: Freddi
authors.forename: Aharon
authors.initials: A
authors.lastname: Gedanken
authors.forename: Artur
authors.initials: A
authors.lastname: Cavaco-Paulo
mesh_terms: D000818:Animals; D002417:Cattle; D005349:Fibroins / Q000737:chemistry / Q000378:metabolism*; D017348:Microscopy, Electron, Scanning Transmission; D008863:Microspheres; D056004:Molecular Dynamics Simulation; D009821:Oils / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D053481:Secretory Leukocyte Peptidase Inhibitor / Q000737:chemistry / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism*; D012997:Solvents / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D009821:Oils; D010446:Peptide Fragments; D053481:Secretory Leukocyte Peptidase Inhibitor; D012997:Solvents; D012710:Serum Albumin, Bovine; D005349:Fibroins