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Kaklamani, Georgia; Cheneler, David; Bowen, James; Anthony, Carl J.; Grover, Liam M. and Adams, Michael J.
(2013).
URL: https://www.academia.edu/9852224/Towards_rapid_man...
Abstract
Hydrogels have been widely used in biomedical applications such as scaffolds for tissue engineering, biosensing, drug delivery and cell immobilization. Due to their 3D structure, tunable mechanical properties, and their ability to mimic the cellular environment, these materials have been extensively studied and analysed in order to investigate their potential characteristics in the biomaterials field. Alginate is one of the most commonly used hydrogels, which is derived from brown algae, a polysaccharide that is composed of (1-4)-linked β-D-mannuronic acid and α-L-guluronic acid monomers. The crosslinks within the alginate hydrogel typically utilize divalent cations to co-ordinate carboxyl and hydroxyl moieties on the polymer chain.
Employing a novel system geometry for rapid manufacture, we report an in-depth study of the variables that can be used to modulate the mechanical and rheological properties of the resultant tissue analogue. Specifically we investigate the influence of (i) the divalent cation, (ii) the cation concentration, (iii) the alginate concentration, (iv) the composition of the aqueous medium, and (v) fibroblast encapsulation and concentration in the hydrogel. Spherical indentation is employed to measure the short-time Young’s modulus as a means of characterising the mechanical properties. More detailed rheological properties are obtained by transient and oscillatory measurements with a parallel plate configuration. Staining protocols were used to verify cellular viability in the hydrogel post-manufacture. It is shown that the hydrogel modulus can be tailored up to approximately 500 kPa through careful selection of the alginate and cation concentration. Furthermore, fibroblast viability is not attenuated upon incorporation into the hydrogel; a range of cell growth media can be used without influencing mechanical properties.