Figure 1: Spontaneous spheroid formation of CBDCs. On a conventional monolayer culture plate, adhered CBDCs showed fibroblast-like morphology and stable growth (a–c). On spheroid-forming plates, CBDCs began to form spheroids at 12 hours (d) and were maintained during the observation period (e and f). The number of spheroids peaked at 24 hours and then plateaued. The change in spheroid number between 24 hours and 72 hours was not statistically significant but was significant between 12 hours and 24 hours () and also between 12 hours and 72 hours (), (g). The average diameter of spheroids decreased gradually during the time course without statistically significant changes, (h). Scale . Data are represented as the . and .