Nanocomposite-coated porous templates for engineered bone scaffolds: A parametric study of layer-by-layer assembly conditions

Monika Ziminska, Marine J Chalanqui, Philip Chambers, Jonathan Acheson, Helen McCarthy, Nicholas Dunne, Andrew Hamilton

Research output: Contribution to journalArticle

Abstract

Using the layer-by-layer (LbL) assembly technique to deposit mechanically reinforcing coatings onto porous templates is a route for fabricating engineered bone scaffold materials with a combination of high porosity, strength, and stiffness. LbL assembly involves the sequential deposition of nano- to micro-scale multilayer coatings from aqueous solutions. Here, a design of experiments (DOE) approach was used to evaluate LbL assembly of polyethyleneimine (PEI), polyacrylic acid (PAA), and nanoclay coatings onto open-cell polyurethane foam templates. The thickness of the coatings, and the porosity, elastic modulus and collapse stress of coated foam templates were most strongly affected by the pH of PAA solutions, salt concentration, and interactions between these factors. The mechanical properties of coated foams correlated with the thickness of the coatings, but were also ascribed to changes in the coating properties due to the different assembly conditions. A DOE optimization aimed to balance the trade-off between higher mechanical properties but lower porosity of foam templates with increasing coating thickness. Micromechanical modelling predicted that deposition of 116 QLs would achieve mechanical properties of cancellous bone (>0.05 GPa stiffness and >2 MPa strength) at a suitable porosity of >70%. When capped with a final layer of PAA and cross-linked via thermal treatment, the PEI/PAA/PEI/nanoclay coatings exhibited good indirect cytotoxicity with mesenchymal stem cells. The ability of LbL assembly to deposit a wide range of functional constituents within multilayer-structured coatings makes the general strategy of templated LbL assembly a powerful route for fabricating engineered tissue scaffolds that can be applied onto various porous template materials to achieve a wide range of properties, pore structures, and multifunctionality.
LanguageEnglish
JournalBiomedical Materials
DOIs
Publication statusPublished - 15 Aug 2019

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carbopol 940
Scaffolds
Nanocomposites
Bone
Coatings
Polyethyleneimine
Porosity
Foams
Mechanical properties
Design of experiments
Multilayers
Deposits
Stiffness
Tissue Scaffolds
Cytotoxicity
Pore structure
Stem cells
Salts
Elastic moduli
Heat treatment

Cite this

Ziminska, Monika ; Chalanqui, Marine J ; Chambers, Philip ; Acheson, Jonathan ; McCarthy, Helen ; Dunne, Nicholas ; Hamilton, Andrew. / Nanocomposite-coated porous templates for engineered bone scaffolds: A parametric study of layer-by-layer assembly conditions. 2019.
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Nanocomposite-coated porous templates for engineered bone scaffolds: A parametric study of layer-by-layer assembly conditions. / Ziminska, Monika; Chalanqui, Marine J; Chambers, Philip; Acheson, Jonathan; McCarthy, Helen; Dunne, Nicholas; Hamilton, Andrew.

15.08.2019.

Research output: Contribution to journalArticle

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AU - Chalanqui, Marine J

AU - Chambers, Philip

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AU - Dunne, Nicholas

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