Figure 13: Model I. Base matrix layer is photocured ST gelatin gel. A mixed solution of ECs (1×107 cells/ml) and 0.2% collagen was dispensed onto the gel (operational parameters: pressure, 0.05 MPa; dispenser movement rate, 90 mm/s; valve opening, 3%), and subsequently overlayered with ST-gelatin solution followed by photoirradiation, resulting in upper gels with thickness of 2 mm. Cells were cultured for up to 4 days (C).