Rheological Characterisation of Different Alginate-Based Hydrogels for a Biomimetic Representation of a Tooth

Abstract

Introduction In bioprinting, it is essential to correctly characterise the materials to be used in order to ensure the highest cell viability while maintaining the best structural properties of the hydrogels. Methods Alginate-based hydrogels with different concentrations have been characterised because they are currently the ones with the best printing properties according to the literature. The concentrations chosen were 3.5%, 4% and 5% alginate, and then a scaffold was bioprinted with the one with the best mechanical properties. Finally, a 3D model of a tooth was bioprinted to check the integrity of the hydrogel characterised as a somewhat more complex structure than a simple scaffold. Results It could be observed that, despite suffering a similar viscosity loss to the rest, the sample with the best viscosity properties when subjected to shear stresses was the one containing 5% alginate concentration. When a simple scaffold was bioprinted, it was observed that the result was positive, as the visual analysis corresponded to the parameters programmed in 3D design software. Likewise, the subsequent bioprinting of the dental model showed good results. Conclusions The hydrogels characterised by rheometry showed similar behaviour with respect to viscosity. Furthermore, it was found that the hydrogel with higher viscosity allowed for higher quality bioprints.