Structural and Mechanical Properties of Thin Films of Bovine Submaxillary Mucin versus Porcine Gastric Mucin on a Hydrophobic Surface in Aqueous Solutions.
The structural and mechanical properties of thin films generated from two types of mucins, namely, bovine submaxillary mucin (BSM) and porcine gastric mucin (PGM) in aqueous environment were investigated with several bulk and surface analytical techniques. Both mucins generated hydrated films on hydrophobic polydimethylsiloxane (PDMS) surfaces from spontaneous adsorption arising from their amphiphilic characteristic. However, BSM formed more elastic films than PGM at neutral pH condition. This structural difference was manifested from the initial film formation processes to the responses to shear stresses applied to the films. Acidification of environmental pH led to strengthening the elastic character of BSM films with increased adsorbed mass, whereas an opposite trend was observed for PGM films. We propose that this contrast originates from that negatively charged motifs are present for both the central and terminal regions of BSM molecule, whereas a similar magnitude of negative charges is localized at the termini of PGM molecule. Given that hydrophobic motifs acting as an anchor are also localized in the terminal region, electrostatic repulsion between anchoring units of PGM molecules on a nonpolar PDMS surface leads to weakening of the mechanical integrity of the films.
Department of Mechanical Engineering, Technical University of Denmark , 2800 Kongens Lyngby, Denmark.
Jan Busk
JB
Madsen
Department of Biomedical Sciences, Faculty of Health and Societyand Biofilms-Research Center for Biointerfaces, Malmö University , 20506, Malmö, Sweden.
Javier
J
Sotres
Department of Mechanical Engineering, Technical University of Denmark , 2800 Kongens Lyngby, Denmark.
Kirsi I
KI
Pakkanen
Department of Mechanical Engineering, Technical University of Denmark , 2800 Kongens Lyngby, Denmark.
Petr
P
Efler
Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark , 2800 Kongens Lyngby, Denmark.
Birte
B
Svensson
Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark , 2800 Kongens Lyngby, Denmark.
Maher
M
Abou Hachem
Department of Biomedical Sciences, Faculty of Health and Societyand Biofilms-Research Center for Biointerfaces, Malmö University , 20506, Malmö, Sweden.
Thomas
T
Arnebrant
Department of Mechanical Engineering, Technical University of Denmark , 2800 Kongens Lyngby, Denmark.
Seunghwan
S
Lee
D000327:Adsorption; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D009077:Mucins / Q000737:chemistry / Q000378:metabolism*; D058525:Quartz Crystal Microbalance Techniques; D013363:Submandibular Gland / Q000737:chemistry / Q000378:metabolism*; D013499:Surface Properties; D013552:Swine; D014867:Water / Q000737:chemistry
D009077:Mucins; D014867:Water