Relationship between shear-thinning rheological properties of bioinks and bioprinting parameters

Abstract

Three-dimensional bioprinting is a technology in constant development, mainly due to its extraordinary potential to revolutionize regenerative medicine. It allows fabrication through the additive deposition of biochemical products, biological materials, and living cells for the generation of structures in bioengineering. There are various techniques and biomaterials or bioinks that are suitable for bioprinting. Their rheological properties are directly related to the quality of these processes. In this study, alginate-based hydrogels were prepared using CaCl2 as ionic crosslinking agent. Their rheological behavior was studied, and simulations of the bioprinting processes under predetermined conditions were carried out, looking for possible relationships between the rheological parameters and the variables used in the bioprinting processes. A clear linear relationship was found between the extrusion pressure and the flow consistency index rheological parameter, k, and between the extrusion time and the flow behavior index rheological parameter, n. This would allow simplification of the repetitive processes currently applied to optimize the extrusion pressure and dispensing head displacement speed, thereby helping to reduce the time and material used as well as to optimize the required bioprinting results.

Characterization of a Chimeric Resilin-Elastin Structural Protein Dedicated to 3D Bioprinting as a Bioink Component

“…The dynamic viscosity values in hydrogels containing the recombinant protein are RE15mR(0.1)-11.36 Pa•s, RE15mR(0.5)-13.90 Pa•s, and RE15mR(1.5)-17.33 Pa•s, respectively, while for the reference sample the viscosity is 24.11 Pa•s. The addition of the RE15mR recombinant protein to the hydrogel resulted in an increase in dynamic viscosity; the higher the protein concentration, the higher the viscosity of the biomaterial, which may be important for the use of this material in bioprinting technology [44,45]. The dynamic viscosity values in bioinks containing the recombinant protein are A15(0.1)-0.33 Pa•s and A15(1.5)-0.59 Pa•s, respectively, while for the reference sample the viscosity is 0.46 Pa•s.…”

The influence of viscosity of hydrogels on the spreading and migration of cells in 3D bioprinted skin cancer models

“…Increased G′ that is consistently higher than G″ indicates improved elastic properties over viscous properties. Determining these properties of the hydrogel bioink before bioprinting gives an indication of printability, stable physical properties, and the ability to maintain shape without collapsing after bioprinting ( Das and Basu, 2019 ; Xu L et al, 2022b ; Sánches-Sánches et al, 2023 ).…”

A review on biopolymer-based bioinks for 3D bioprinting

“…12,14 Moreover, the characteristics of bioink can be altered by the pressure experienced as it is extruded through the nozzle, making it essential for an ideal bioink to behave as a shearthinning fluid under pressure and to retain its structural integrity postextrusion by exhibiting a viscoelastic response. 5,10,15 Additionally, the solidification of bioink from a gel state after extrusion, known as the gelation process, impacts both cell viability and the resolution of bioprinting. 10 Optimizing the gelation time of bioinks is essential not only for supporting self-sustaining structures but also for avoiding uneven cell distribution and preventing nozzle blockages.…”