TY - GEN
T1 - Bioprinting of liquid hydrogel precursors in a support bath by analyzing two key features
T2 - ASME 2018 13th International Manufacturing Science and Engineering Conference, MSEC 2018
AU - Ding, Houzhu
AU - Chang, Robert C.
N1 - Publisher Copyright:
Copyright © 2018 ASME.
PY - 2018
Y1 - 2018
N2 - Microextrusion-based bioprinting within a support bath material is an emerging additive manufacturing technique for fabricating complex three-dimensional (3D) tissue constructs. However, there exists fundamental knowledge gaps in understanding the spatiotemporal mapping of cells within the bioprinted constructs and their shape fidelity when embedded in a support bath material. To address these questions, this paper advances quantitative analyses to systematically determine the spatial distribution for cell-laden filament-based tissue constructs as a function of the bio-ink properties. Also, optimal bio-ink formulations are investigated to fabricate complex 3D structures with superior shape integrity. Specifically, for a 1D filament printed in a support bath, cells suspended in low viscosity liquid hydrogel precursors are found to exhibit a characteristic non-uniform distribution as measured by a degree of separation (Ds) metric. In a 2D square wave pattern print, cells are observed to flow and aggregate downstream at certain positions along the in-plane print direction. In a 3D analysis, owing to the high cell density and gravity effects, a non-uniform cell distribution within a printed cylindrical structure is observed in the build direction. From the structural standpoint, the addition of CaCl2 to the support bath activates the hydrogel cross-linking process during printing, resulting in 3D prints with enhanced structural outcomes. This multidimensional print analysis provides evidence that, under the emerging bioprinting support bath paradigm, the printable parameter space can be extended to low viscosity liquid hydrogel precursor materials that can be systematically characterized and optimized for key process performance outcomes in cell distribution and shape fidelity.
AB - Microextrusion-based bioprinting within a support bath material is an emerging additive manufacturing technique for fabricating complex three-dimensional (3D) tissue constructs. However, there exists fundamental knowledge gaps in understanding the spatiotemporal mapping of cells within the bioprinted constructs and their shape fidelity when embedded in a support bath material. To address these questions, this paper advances quantitative analyses to systematically determine the spatial distribution for cell-laden filament-based tissue constructs as a function of the bio-ink properties. Also, optimal bio-ink formulations are investigated to fabricate complex 3D structures with superior shape integrity. Specifically, for a 1D filament printed in a support bath, cells suspended in low viscosity liquid hydrogel precursors are found to exhibit a characteristic non-uniform distribution as measured by a degree of separation (Ds) metric. In a 2D square wave pattern print, cells are observed to flow and aggregate downstream at certain positions along the in-plane print direction. In a 3D analysis, owing to the high cell density and gravity effects, a non-uniform cell distribution within a printed cylindrical structure is observed in the build direction. From the structural standpoint, the addition of CaCl2 to the support bath activates the hydrogel cross-linking process during printing, resulting in 3D prints with enhanced structural outcomes. This multidimensional print analysis provides evidence that, under the emerging bioprinting support bath paradigm, the printable parameter space can be extended to low viscosity liquid hydrogel precursor materials that can be systematically characterized and optimized for key process performance outcomes in cell distribution and shape fidelity.
KW - 3D Bioprinting
KW - Cell Distribution
KW - Gelatinalginate
KW - Hydrogel
KW - Shape fidelity
KW - Support Bath
UR - http://www.scopus.com/inward/record.url?scp=85055056092&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85055056092&partnerID=8YFLogxK
U2 - 10.1115/MSEC2018-6675
DO - 10.1115/MSEC2018-6675
M3 - Conference contribution
AN - SCOPUS:85055056092
SN - 9780791851357
T3 - ASME 2018 13th International Manufacturing Science and Engineering Conference, MSEC 2018
BT - Additive Manufacturing; Bio and Sustainable Manufacturing
Y2 - 18 June 2018 through 22 June 2018
ER -