Page 132 - IJB-10-6

International Journal of Bioprinting Fluid mechanics of extrusion bioprinting

(A)

(B) (C)

Figure 4. Parameters and outcomes of Chirianni et al. model for cell damage prediction. (A)
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Figure 4. Parameters and outcomes of Chirianni et al. model for cell damage prediction. (A) Equivalent area (A ) versus nozzle cross-sectional area
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eq
(A). Qualitative description of the model parameters effect on cell distribution and A in Equation XII. (B and C) Comparison of cell damage prediction
eq
) versus nozzle cross-sectional area (). Qualitative description of the model
Equivalent area (
by Chirianni et al. using the model (or Equation X) and the experimental results reported by Han et al. (Scenario 1) and Li et al. (Scenario 2) for
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(B) printing with a given nozzle diameter and various printing pressures, and (C) given printing pressure and various nozzle diameter. Reprinted with
permission from ref. , Copyright© (2024) Elsevier. in Equation XII. (B and C) Comparison of cell
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parameters effect on cell distribution and
Herschel–Bulkley fluids are suitable for extrusion to be transported without experiencing shear stress. When
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bioprinting because their viscosity changes favorably, cells are incorporated into the bioink, the yield stress helps
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enhancing cell viability and printability. Additionally, their maintain the uniform distribution of the encapsulated cells,
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yield stress prevents dripping from the nozzle, improving promoting homogeneity, Bioinks with low yield stress are
shape fidelity after printing. If shear stress is lower than susceptible to issues like cell settling or phase separation.
the yield value, there is no movement in the fluid, thus Conversely, high-yield stress can potentially have adverse
preventing drips in bioprinting. Another benefit of utilizing effects on cells when the flow is initiated. 88,89
fluids with yield stress as bioinks is the formation of a plug While power-law, Carreau, or Cross fluids are not
flow region within the central area of the dispensing needle. classified as yield fluids, their high limiting zero-shear
In this region, shear stress is reduced to zero, allowing cells viscosity resembles yield behavior to some extent. At low
Volume 10 Issue 6 (2024) 124 doi: 10.36922/ijb.3973