Influence of ionic strength changes on the structure of pre-adsorbed salivary films. A response of a natural multi-component layer

Macakova, Lubica, Yakubov, Gleb E., Plunkett, Mark A. and Stokes, Jason R. (2010) Influence of ionic strength changes on the structure of pre-adsorbed salivary films. A response of a natural multi-component layer. Colloids and Surfaces B: Biointerfaces, 77 1: 31-39. doi:10.1016/j.colsurfb.2009.12.022


Author Macakova, Lubica
Yakubov, Gleb E.
Plunkett, Mark A.
Stokes, Jason R.
Title Influence of ionic strength changes on the structure of pre-adsorbed salivary films. A response of a natural multi-component layer
Journal name Colloids and Surfaces B: Biointerfaces   Check publisher's open access policy
ISSN 0927-7765
1873-4367
Publication date 2010-05-01
Sub-type Article (original research)
DOI 10.1016/j.colsurfb.2009.12.022
Volume 77
Issue 1
Start page 31
End page 39
Total pages 9
Place of publication Amsterdam, Netherlands
Publisher Elsevier B.V.
Collection year 2011
Language eng
Abstract Salivary films coating oral surfaces are critically important for oral health. This study focuses on determining the underlying nature of this adsorbed film and how it responds to departures from physiological conditions due to changes in ionic strength. Under physiological conditions, it is found that pre-adsorbed in vitro salivary film on hydrophobic surfaces is present as a highly hydrated viscoelastic layer. We follow the evolution of this film in terms of its effective thickness, hydration and viscoelastic properties, as well as adsorbed mass of proteins, using complementary surface characterisation methods: a Surface Plasmon Resonance (SPR) and a Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D). Our results support a heterogeneous model for the structure of the salivary film with an inner dense anchoring layer and an outer highly extended hydrated layer. Further swelling of the film was observed upon decreasing the salt concentration down to 1 mM NaCl. However, upon exposure to deionised water, a collapse of the film occurs that was associated with the loss of water contained within the adsorbed layer. We suggest that the collapse in deionised water is driven by an onset of electrostatic attraction between different parts of the multi-component salivary film. It is anticipated that such changes could also occur when the oral cavity is exposed to food, beverage, oral care and pharmaceutical formulations where drastic changes to the structural integrity of the film is likely to have implications on oral health, sensory perception and product performance. © 2010 Elsevier B.V. All rights reserved.
Keyword Saliva
Adsorbed film
Surface Plasmon resonance
Quartz crystal microbalance
Hydration
Viscoelastic properties
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemical Engineering Publications
Official 2011 Collection
 
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Created: Sun, 18 Apr 2010, 00:06:10 EST