Oil-free Microfluidic Spheroid Generation for Cancer Drug Testing

In this thesis, a droplet microfluidics platform for on-chip polymerization of all aqueous hydrogel multicellular spheroids (MCSs) is developed. First, dextran-alginate droplets containing MCF-7 breast cancer cells, surrounded by polyethylene glycol, are generated at a flow-focusing junction. Droplets travel to a second flow-focusing junction where they are introduced to calcium chloride and polymerize on-chip to form hydrogel MCSs. In drug-free experiments, hydrogels are incubated for six days, and cellular viability is evaluated. In drug experiments, to test the effects of a chemotherapy drug, doxorubicin, three drug concentrations and two controls are applied to the spheroids for 48 hours. Image analysis is conducted using confocal microscopy z-stack images and MATLAB. It is shown that in drug-free experiments and conditions, MCSs show strong viability, and in drug experiments, the viability of MCSs decrease with increasing doxorubicin concentration.