Fig. 8.

Spatiotemporally controlled vascular network organization within control-aptamer-functionalized bi-phasic cell-laden hydrogels. (A) Immunostained maximum projection confocal images showing von Willebrand factor (vWF) expression (green) as a marker for endothelial cells and α-smooth muscle actin (α-SMA) (red) as a marker for MSCs differentiation to mural cells, within the HUVECs and MSCs co-cultured, bi-phasic hydrogels (with or without CS treatment on day4). The representative photographic image of the actual bi-phasic hydrogel, showing two distinct sides (one with aptamer and other one without) with a distinct interface. Considering its big size, each hydrogel was categorized into four regions; near aptamer- and near GelMA-side being in immediate vicinity of the interface, whereas far aptamer- and far GelMA-side were at the far end from the interface. Scale bar is 200 μm. Orthogonal views of the confocal z-stacks showing (B) vWF + α-SMA stained samples & (C) F-actin Phalloidin + VE-Cadherin stained samples, at higher magnification, showing the developing vascular networks. At the cross-section of the developing vessel, a round lumen like vascular structure could be observed in orthogonal view. The scale bar is 50 μm. Quantification of vWF + stained vessel network in these samples using Angiotool Software on day5 (D) and day10 (E). The values are represented as mean ± SD, along with individual data points. The calculations were performed with three technical replicates, n = 3. The statistical significance was calculated using two-way ANOVA with tukey's post-hoc test were *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 and ns means not significant.