On-chip formation and perfusion culture of 3D tumor spheroids using gravity-driven cell aggregation and pumpless balanced droplet dispensing

This paper presents a 3D tumor spheroid chip for the on-chip formation and perfusion culture of spheroids using gravity-driven cell aggregation and pumpless balanced droplet dispensing. In the experimental study, we verify the present chip successfully forms H358, H23, and A549 human lung cancer cell spheroids in the diameter range of 220μm~3.2mm (uniformity>;90%). In the spheroid culture test at the medium perfusion rates, Q, of 0.1~0.3μl/min, the H358 spheroid with the initial diameter of 376.4μm shows the average cell proliferation rate of 16.4%/day which is 4.5 fold higher than 3.61%/day of static culture. We also verify the perfusion culture of H358 spheroids at Q of 0.1~0.3μl/min results in the average viability of 82.4% higher than 68.9% in the static culture. The present chip achieves on-chip formation and pumpless perfusion culture of 3D spheroids with simple structure, thus being potential for use in the integrated spheroid-based cell chips.