Investigation of the intrinsic permeability of ice-templated collagen scaffolds as a function of their structural and mechanical properties.
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Mohee, L., Offeddu, G., Husmann, A., Oyen, M., & Cameron, R. (2019). Investigation of the intrinsic permeability of ice-templated collagen scaffolds as a function of their structural and mechanical properties.. Acta biomaterialia, 83 189-198. https://doi.org/10.1016/j.actbio.2018.10.034
Collagen scaffolds are widely used in a range of tissue engineering applications, both in vitro and in vivo, where their permeability to fluid flow greatly affects their mechanical and biological functionality. This paper reports new insights into the interrelationships between permeability, scaffold structure, fluid pressure and deformation in collagen scaffolds, focussing in particular on the degree of closure and the alignment of the pores. Isotropic and aligned scaffolds of different occlusivity were produced by ice templating, and were characterised in terms of their structure and mechanical properties. Permeability studies were conducted using two experimental set-ups to cover a wide range of applied fluid pressures. The permeability was found to be constant at low pressures for a given scaffold with more open structures and aligned structures being more permeable. The deformation of scaffolds under high pressure led to a decrease in permeability. The aligned structures were more responsive to deformation than their isotropic equivalents with their permeability falling more quickly at low strain. For isotropic samples, a broad (1- ɛ)2 dependence for permeability was observed with the constant of proportionality varying with collagen fraction as the starting structures became more occluded. Aligned scaffolds did not follow the same behaviour, with the pores apparently closing more quickly in response to early deformation. These results highlight the importance of scaffold structure in determining permeability to interstitial fluid, and provide an understanding of scaffold behaviour within the complex mechanical environment of the body.
Collagen, Ice, Permeability, Porosity, Models, Chemical, Tissue Scaffolds
This research was supported by the European Research Council (Advanced Grant 320598 3D-E). Financial support for L.M was provided via the Cambridge Trust Scholarship and the departmental funding of Materials Science and Metallurgy, University of Cambridge.
European Research Council (320598)
External DOI: https://doi.org/10.1016/j.actbio.2018.10.034
This record's URL: https://www.repository.cam.ac.uk/handle/1810/286418