(570a) Rapid Microfluidic Production of Cell-Laden Hydrogel Microspheroids | AIChE

(570a) Rapid Microfluidic Production of Cell-Laden Hydrogel Microspheroids

Authors 

Lipke, E. - Presenter, Auburn University
Tian, Y., Auburn University
Seeto, W. J., Auburn University
Pradhan, S., Auburn University
Kerscher, P., Auburn University

There
has been an increasing need for rapid production of microspheroidal tissues from
various applications, including therapeutic cell delivery, bioreactor-based
cell production, 3D disease modeling for high-throughput drug screening, and 3D
bioprinting. Cells are encapsulated in hydrogels, which provide 3D scaffolds
for cell proliferation and work as protections for cells during these processes.
Microfluidic systems have been widely used for production of cell-laden
hydrogel microspheroids. However,
most current microfluidic systems require costly microfabrication facilities
for device fabrication and can only produce small microspheroids (diameters
< 200 µm) with low cell densities (< 10 million cells/mL) and slow
production rates (polymerization time > 20s) using limited types of
materials. These constraints impede their use in the downstream applications.

This study established a
robust microfluidic cell encapsulation platform. Unlike other systems,
our established platform uses a flexible, low cost, custom-developed molding
technique for microfluidic device fabrication, which overcomes the limitations
imposed by traditional photolithographic microfluidic chip fabrication. The
established platform is compatible with multiple biomaterials (PEGDA,
PEG-fibrinogen, and GelMA) and cell types (hiPSCs, breast cancer cells, and
endothelial colony forming cells), and can produce highly uniform
microspheroids (intra- and inter-batch coefficient of variance was 2% for
diameter and 1% for roundness) with high cell densities (10-60 million
cells/mL) and a wide range of diameters (300-1100 μm) through rapid
photocrosslinking (approximate 1 s). As a result of our platform design, the
encapsulated cells are evenly distributed through the microspheroids and
maintain high viability and normal cellular activities in long-term culture
post-encapsulation. As the major component of the platform, our microfluidic
devices employ a modified T-junction design; our unique design provides control
over microspheroid axial ratio and diameter and stable operation at the
required high cell densities and rapid flow rates required for realizing
downstream applications. We achieved high reproducibility; the resulting
microspheroids are uniform both within and between batches, even when
encapsulating cell clusters, which is technically challenging and is generally
not feasible using microfluidic approaches.

In conclusion, this study established a robust microfluidic cell
encapsulation platform fabricated with a new molding technique that enables
quick device fabrication and ready testing and design iteration. Employing this
platform, we rapidly encapsulated multiple types of mammalian cells in hydrogel
microspheroids at much faster rates and higher cell densities than previously
achieved, representing a significant advance over established systems for
scale-up production of cell-laden hydrogel microspheroids.