Fig. 4

Bioprinting of non-linear organoids. MCF12A cells were printed in 40-cell clusters in a radial pattern with print spacings of (a) 500 μm, (b) 400 μm, and (c) 300 μm. (a1–c1) Image of printed cell clusters 7 days after print demonstrating early development into individual organoids. (a2–c2) Image of printed cell clusters 14 days after print demonstrating fusion of individual organoids into a contiguous circular organoid. (d) Image of red fluorescent protein–positive (RFP⁺) MCF12A cells forming large circular organoid 14 days after print. (e) Example of a large circular organoid 24 days after print measuring about 4 mm in diameter. (f) Hematoxylin and eosin (H&E) cross-section of circular organoid shown in e demonstrating luminal sections within the organoid. Scale bars = 500 μm