Cartilage-like electrostatic stiffening of responsive cryogel scaffolds
Nature Publishing Group
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Offeddu, G., Mela, I., Jeggle, P., Henderson, R., Smoukov, S., & Oyen, M. (2017). Cartilage-like electrostatic stiffening of responsive cryogel scaffolds. Scientific Reports, 7 (42948)https://doi.org/10.1038/srep42948
Cartilage is a structural tissue with unique mechanical properties deriving from its electrically-charged porous structure. Traditional three-dimensional environments for the culture of cells fail to display the complex physical response displayed by the natural tissue. In this work, the reproduction of the charged environment found in cartilage is achieved using polyelectrolyte hydrogels based on polyvinyl alcohol and polyacrylic acid. The mechanical response and morphology of microporous physically-crosslinked cryogels are compared to those of heat-treated chemical gels made from the same polymers, as a result of pH-dependent swelling. In contrast to the heat-treated chemically-crosslinked gels, the elastic modulus of the physical cryogels was found to increase with charge activation and swelling, explained by the occurrence of electrostatic stiffening of the polymer chains at large charge densities. At the same time, the permeability of both materials to fluid flow was impaired by the presence of electric charges. This cartilage-like mechanical behavior displayed by responsive cryogels can be reproduced in other polyelectrolyte hydrogel systems to fabricate biomimetic cellular scaffolds for the repair of the tissue.
bioinspired materials, biomedical engineering, mechanical engineering
Is supplemented by: https://doi.org/10.17863/CAM.6832
G.S.O. and M.L.O. 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. I.M. and R.M.H. were supported by the Biotechnology and Biological Research Council, grant BB/J018236/1. P.J. was supported by Kidney Research UK. S.K.S. was supported by the European Research Council (ERC), grant EMATTER (#280078).
European Research Council (280078)
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External DOI: https://doi.org/10.1038/srep42948
This record's URL: https://www.repository.cam.ac.uk/handle/1810/263347