Continuously perfused microbubble array for 3D tumor spheroid model

Abstract

Multi-cellular tumor spheroids ͑MCTSs͒ have been established as a 3D physiologically relevant tumor model for drug testing in cancer research. However, it is difficult to control the MCTS testing parameters and the entire process is timeconsuming and expensive. To overcome these limitations, we developed a simple microfluidic system using polydimethylsiloxane ͑PDMS͒ microbubbles to culture tumor spheroids under physiological flow. The flow characteristics such as streamline directions, shear stress profile, and velocity profile inside the microfluidic system were first examined computationally using a COMSOL simulation. Colo205 tumor spheroids were created by a modified hanging drop method and maintained inside PDMS microbubble cavities in perfusion culture. Cell viability inside the microbubbles was examined by live cell staining and confocal imaging. E-selectin mediated cell sorting of Colo205 and MDA-MB-231 cell lines on functionalized microbubble and PDMS surfaces was achieved. Finally, to validate this microfluidic system for drug screening purposes, the toxicity of the anti-cancer drug, doxorubicin, on Colo205 cells in spheroids was tested and compared to cells in 2D culture. Colo205 spheroids cultured in flow showed a threefold increase in resistance to doxorubicin compared to Colo205 monolayer cells cultured under static conditions, consistent with the resistance observed previously in other MCTS models. The advantages presented by our microfluidic system, such as the ability to control the size uniformity of the spheroids and to perform real-time imaging on cells in the growth platform, show potential for high throughput drug screening development.

Migration and vascular lumen formation of endothelial cells in cancer cell spheroids of various sizes

“…8 For instance, spheroids with various sizes are unable to provide reliable information for drug testing due to the size dependent resistance of tumor spheroids. Many researchers have developed various microfluidic devices for formation and culture of tumor spheroids [9][10][11][12] or differentiation of embryoid bodies. 13,14 Some devices were recently used for drug testing on carcinoma spheroids.…”

A microfluidic device for uniform-sized cell spheroids formation, culture, harvesting and flow cytometry analysis

“…Recently, researchers have developed various spheroid formation and culture devices based on microfluidics techniques. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] A multilayer microfluidic device with a porous membrane was employed to achieve both the spheroid formation and in-situ culture. 24 A microfluidic array platform containing concave microwells and flat cell culture chambers for EB formation and its culture was also developed.…”

Organs-on-a-Chip: A Focus on Compartmentalized Microdevices

“…Microfluidic systems are then able to dynamically perfuse the compartmentalized spheroids, allowing for improved nutrient and waste transport, similar to a tumor adjacent to capillaries in vivo. 1,105 To achieve better simulation of this situation, Walsh et al developed a system to incorporate soluble signaling gradients present in perfused tumors. They characterized growth and diversity of cell states under these physiologically relevant conditions.…”