Figure 1: Establishment of Vascularized Micro-Organs (VMOs).

(a) A schematic of the microfluidic platform. The VMO platform consists of a thick layer of PDMS containing patterned tissue chambers and microfluidic channels, bonded to a thin PDMS membrane and a glass cover slip. Three tissue chambers at the center are connected to two adjacent channels by two capillary burst valves that retain the mixture of cells and ECM inside the chambers. At the two ends of the tissue chambers are two gel loading ports, through which is introduced the cell-ECM suspension. Four media reservoirs are attached to the inlets and outlets of the microfluidic channels. (b) Representative tissue chamber with a fully-developed vascular network on day 7. Lentivirally-transduced EC (ECFC-EC, red) were visualized by confocal microscopy. Supporting stromal cells are unlabeled. EC migrate outward and anastomose with the microfluidic channels. (Scale bar 100 μm) (c) Representative time course of vascular network development (day 2, 4 and 6) (scale bar 100 μm). (d) Representative time course of 70 kDa FITC-dextran perfusion through the vascular network on day 7. Inflow was top left and outflow bottom right. The vascular network is fully perfused within 15 minutes. EC were labeled with mCherry. (Scale bar 100 μm). (e) Confocal imaging of lentivirally-transduced EC (red) and stromal cells (yellow) reveals that many take up a perivascular position. High magnification views on the right. (f) Immunostaining for PDGFR-β and NG2 (both green). EC are expressing mCherry. (g) Collagen IV staining (blue) identifies basement membrane deposition.