Fig. 5

ESP-induced migration of H69 and LX2 cells cultured in a three-dimensional (3D) microfluidic device. A Schematic of cell culture in a 3D microfluidic device, ESP application to each channel (left), and phase-contrast image of H69 and LX2 cells cultured on both sides of the center COL1 hydrogel scaffold 24 h after seeding (right). Scale bars: 100 μm; original magnification: ×40. B Phase-contrast images depicting the migration of H69 and LX2 cells toward the COL1 ECM, showing penetrated area of H69 and LX2 cells in response to ESP treatment. Arrowhead indicates the direction of ESP application. CM supplemented with 4 μg/ml ESPs was applied to either the LX2 channel (left) or the H69 (right) channel, and cells were cultured for 3 days. Red dotted lines and arrowheads indicate the migrating areas of LX2 or H69 cells toward the ECM and individual ECM-penetrating cells, respectively. Scale bars: 100 μm; original magnification: ×40. C Quantification of LX2 and H69 cells migrating to the COL1 ECM. Data represent the mean ± SE. Single asterisk represents a significant difference at *P < 0.05, for Con vs H69 Direct; hash signs indicate a significant difference at ^#P < 0.05 and ^##P < 0.01, for Con vs LX2 Direct; dollar sign indicates a significant difference at ^$P < 0.05, for H69 Direct vs LX2 Direct. CM, Conditioned medium; COL1, type I collagen; Con, untreated control; Con Direct, ECM, extracellular matrix; ESPs, excretory-secretory products; H69 Direct, ESPs applied to a H69 channel; LX2 Direct, ESPs applied to a LX2 channel SE, standard error