<p><i>3D bio-printing is an emerging technology to fabricate tissue scaffold in-vitro through the controlled allocation of biomaterial and cell, which can mimic the in-vivo counterpart of living tissue. Live cells are often encapsulated into the biomaterials (i.e., bio-ink) and extruded by controlling the printing parameters. The functionality of the bioink depends upon three factors: (a) printability, (b) shape fidelity, and (c) bio-compatibility. Increasing viscosity will improve the printability and the shape fidelity; but will require higher applied extrusion pressure, which is detrimental to the living cell dwelling in the bio-ink, which is often ignored in bio-ink optimization process. In this paper, we demonstrate a roadmap to develop bio-inks ensuring the printability, shape fidelity, and cell survivability, simultaneously. The pressure exerted on the bio-ink during extrusion processes is measured analytically and the information is incorporated in the rheology design of the bio-ink. Cell-laden filament is fabricated with Human Embryonic Kidney (HEK 293) cell and analyzed the cell viability. The overall cell viability of the filament fabricated with 8 psi and 12 psi is 90% and 74 % respectively. Additionally, a crossectional live-dead assay of the printed filament with HEK 293 cell is performed which demonstrates the spatial pattern that matches our findings as well. &nbsp;</i></p>

A Rheological Study of Bio-Ink: Shear Stress and Cell Viability

Paper Proceedings: https://asmedigitalcollection.asme.org/MSEC/MSEC2021/volume/85062

2021 International Manufacturing Science and Engineering Conference (MSEC2021)

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