Figure 3.

Applications of the methodology. In vitro tumor sustenance: a) Schematic showing the process by which MDA-MB-231 tumors grown in mice were excised, fragmented, and encapsulated within a vascularized construct, before being perfused over multiple weeks. b) Image showing tumor fragments encapsulated within a vascularized construct with a sinusoidal geometry. c) Fluorescent confocal images of GFP-labeled MDA-MB-231 tumor fragments after 24 d of perfusion within a vascularized construct. The location of the vascular channel is outlined in yellow. Because of the thickness and positioning of the tumor fragments, capturing the vascular channel and tumor fragments within the same plane was not possible. Scale bars: 300 μm. d) Absorbance measurements of MDA-MB-231 tumor fragments sustained over 24 d while encapsulated in either a static matrix or a perfused vascularized construct. Measurements were obtained with a CCK8 assay. To account for the variability introduced by tumor fragments of different sizes, all measurements were normalized with respect to mass (n = 6 with P-value ****P < 0.0001). Hybrid vascularized systems: e) Schematic diagram of a gut-organoid constructed by creating multiple lumens in a single matrix, designed to imitate endothelial and epithelial cocultures. The outer lumen is a 3D spiral, and is seeded with endothelial cells. The inner lumen is a channel and is seeded with gut epithelial cells. f) Image of a multichannel construct generated by evacuating more than one PVA scaffold within a single matrix. g) Fluorescent confocal images of GFP-labeled Caco-2 cells and mCherry-labeled HUVECs seeded, respectively, within an inner linear channel and an outer spiral channel of a vascularized construct. The top image shows a cross-sectional view of the construct. The bottom image shows a close-up of the Caco-2 cells, indicating formation of finger-like protrusions. Scale bars: 1 mm (top) and 100 μm (bottom).