Figure 6
Co-culturing of human AF or NP cells with HMEC-1 cells using microfluidic coculture devices. (A) Schematic of microfluidic experimental design and timeline in this study. The AF or NP cells stimulated with IL-1β were plated into the left-side chamber at an approximate density of 1.0 \(\times \) 105 cells/mL. Thereafter, ECs were plated into the opposite-side chamber. After most ECs in the chamber were plated in a line along a sidewall of the hydrogel collagen surface, IVD and EC cells were co-cultured for seven days and maintained in a humidified atmosphere with 5% CO2 at 37 °C. After incubation for the designated periods, the cells were fixed and immune-stained. Fluorescence images of (B) HMEC-1 to HMEC-1 cells, (C) human AF cells to HMEC-1, and (D) human NP cells to HMEC-1 cultured in the microfluidic platform. Cells were three-dimensionally attached to the surface of collagen hydrogel, where they aggregated. (E) Quantification of migrating cell counts and migration distance from left channels toward the right channel acquired by monolayer images. (F) Quantification of migration and invasion distance of each cell toward the right channel acquired by Z-stacked images. The values are reported as the mean ± standard error of five independent experiments. *p < 0.05, **p < 0.01, and ***p < 0.001 as compared with the HMEC-1 to HMEC-1 culture group. The line indicates comparison with each group. Scale bar of monolayer image = 1000 µm.
