Skip to main content
. Author manuscript; available in PMC: 2022 Apr 8.
Published in final edited form as: Biofabrication. 2021 Apr 8;13(3):10.1088/1758-5090/abe1cf. doi: 10.1088/1758-5090/abe1cf

Figure 2.

Figure 2.

Functionality of the TIME-on-Chip: (A). (i) Experimental investigation of the feasibility of fluid transport across the hybrid integrated TIME-on-Chip device: microscopic images showing the evolution of FITC diffusion across a spheroid at different time points (scale bars represent 100 μm). (ii) Finite-element models based on a 2D geometry of the cross-section of the device simulating the diffusion based fluid transport from the microchannel into the collagen around the spheroids. Sections of the model representing the experimental diffusion condition around the spheroid located away from the microfluidic channel are marked in red dotted lines. (iii) Compared to the experimental data for variation in the rate of fluorophore diffusion across a spheroid, the 2D finite element simulations adequately predict the diffusion-based fluid transport behavior of the device as seen from the average rate of change of concentration. (B). 3D migration behavior of OVCAR-3: (i) representative fluorescence images upon immunostaining of the distorted OVCAR-3 spheroids for E-cadherin (red) and nuclear stain (DAPI blue). OVCAR-3 spheroids showed spontaneous migration when present within a 3D collagen matrix, the spheroid distortion was negligible within the first 24 h and thereafter marginally increased over the next 48 h. Upon stimulation with TGF-β and IL-8, OVCAR-3 cells migrate in clusters and fluorescence immunostaining shows qualitatively a reduced E-cadherin expression throughout the spheroids when stimulated with both IL-8 and TGF-β. Scale bars represent 100 μm. (ii) Compared to unstimulated conditions, spheroids undergo a significantly greater distortion over 24 h when stimulated by IL-8 (p < 0.0001) and TGF-β (p < 0.0001). (iii) The mean E-cadherin signal intensity per spheroid decreases during stimulated migration correlating with the spheroid distortion (data collected from n = 9 spheroids over N = 3 experiments, mean ± SEM. Significance was determined using one-way ANOVA with Tukey’s post-hoc analysis * p < 0.05, ** p < 0.01, ****p < 0.0001, ns = not significant).