Micromechanical model of biphasic biomaterials with internal adhesion: application to nanocellulose hydrogel composites

Bonilla, Mauricio R., Lopez-Sanchez, P., Gidley, M. J. and Stokes, J. R. (2016) Micromechanical model of biphasic biomaterials with internal adhesion: application to nanocellulose hydrogel composites. Acta Biomaterialia, 29 149-160. doi:10.1016/j.actbio.2015.10.032


Author Bonilla, Mauricio R.
Lopez-Sanchez, P.
Gidley, M. J.
Stokes, J. R.
Title Micromechanical model of biphasic biomaterials with internal adhesion: application to nanocellulose hydrogel composites
Journal name Acta Biomaterialia   Check publisher's open access policy
ISSN 1878-7568
1742-7061
Publication date 2016-01-01
Year available 2015
Sub-type Article (original research)
DOI 10.1016/j.actbio.2015.10.032
Open Access Status Not Open Access
Volume 29
Start page 149
End page 160
Total pages 12
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Collection year 2016
Language eng
Formatted abstract
The mechanical properties of hydrated biomaterials are non-recoverable upon unconfined compression if adhesion occurs between the structural components in the material upon fluid loss and apparent plastic behaviour. We explore these micromechanical phenomena by introducing an aggregation force and a critical yield pressure into the constitutive biphasic formulation for transversely isotropic tissues. The underlying hypothesis is that continual fluid pressure build-up during compression temporarily supresses aggregation. Once compression stops and the pressure falls below some critical value, internal aggregation occurs over a time scale comparable to the poroelastic time. We demonstrate this model by predicting the mechanical response of bacterial nanocellulose hydrogel composites, which are promising biomaterials and a structural mimetic for the plant cell wall. Cross-linking of cellulose by xyloglucan creates an extensional resistance and substantially increases the compressive modulus under large compression and densification. In comparison, incorporating non-crosslinking arabinoxylan into the hydrogel has little effect on its mechanics at the strain rates investigated. These results assist in elucidating the mechanical role of these polysaccharides in the complex plant cell wall structure. They also suggest xyloglucan is a suitable candidate to tailor the stiffness of nanocellulose hydrogels in biomaterial design, which includes modulating cell-adhesion in tissue engineering applications. The model and overall approach may be utilised to characterise and design a myriad of biomaterials and mammalian tissues, particularly those with a fibrillar structure.

Statement of Significance

The mechanical properties of hydrated biomaterials can be non-recoverable upon compression due to increased adhesion occurring between the structural components in the material. Cellulose–hemicellulose composite hydrogels constitute a classical example of this phenomenon, since fibres can freely re-orient and adhere upon fluid loss to produce significant variations in the mechanical response to compression. Here, we model their micromechanics by introducing an aggregation force and a critical yield pressure into the constitutive formulation for transversely isotropic biphasic materials. The resulting model is easy to implement for routine characterization of this type of hydrated biomaterials through unconfined compression testing and produces physically meaningful and reproducible mechanical parameters.
Keyword Gel
Cellulose
Composites
Poroelastic
Biphasic model
Compression
Rheology
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemical Engineering Publications
Official 2016 Collection
Centre for Nutrition and Food Sciences Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 3 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 2 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 12 Jan 2016, 00:29:13 EST by System User on behalf of School of Chemical Engineering