Repository logo
 

Multi-scale mechanical response of freeze-dried collagen scaffolds for tissue engineering applications.


Type

Article

Change log

Authors

Offeddu, Giovanni S 
Ashworth, Jennifer C 
Cameron, Ruth E 
Oyen, Michelle L 

Abstract

Tissue engineering has grown in the past two decades as a promising solution to unresolved clinical problems such as osteoarthritis. The mechanical response of tissue engineering scaffolds is one of the factors determining their use in applications such as cartilage and bone repair. The relationship between the structural and intrinsic mechanical properties of the scaffolds was the object of this study, with the ultimate aim of understanding the stiffness of the substrate that adhered cells experience, and its link to the bulk mechanical properties. Freeze-dried type I collagen porous scaffolds made with varying slurry concentrations and pore sizes were tested in a viscoelastic framework by macroindentation. Membranes made up of stacks of pore walls were indented using colloidal probe atomic force microscopy. It was found that the bulk scaffold mechanical response varied with collagen concentration in the slurry consistent with previous studies on these materials. Hydration of the scaffolds resulted in a more compliant response, yet lesser viscoelastic relaxation. Indentation of the membranes suggested that the material making up the pore walls remains unchanged between conditions, so that the stiffness of the scaffolds at the scale of seeded cells is unchanged; rather, it is suggested that thicker pore walls or more of these result in the increased moduli for the greater slurry concentration conditions.

Description

Keywords

Colloidal probe AFM, Indentation, Scaffolds mechanics, Type I collagen, Viscoelastic, Animals, Biomechanical Phenomena, Cattle, Collagen Type I, Elasticity, Freeze Drying, Materials Testing, Mechanical Phenomena, Membranes, Artificial, Tissue Engineering, Tissue Scaffolds, Viscosity

Journal Title

J Mech Behav Biomed Mater

Conference Name

Journal ISSN

1751-6161
1878-0180

Volume Title

42

Publisher

Elsevier BV
Sponsorship
Engineering and Physical Sciences Research Council (EP/G037221/1)
The authors are grateful to the Nano Doctoral Training Centre (NanoDTC), University of Cambridge, and the EPSRC who supported this work through the EP/G037221/1 grant.