Figure 2.

3D Bioprinted Spheroids Have a Similar Organization as Manually Produced Spheroids

(A) 3D rendered and 3D cross-sectioned (via optical sectioning) light-sheet microscopy images of the 3D bioprinted (left) and manual (right) SK-N-BE(2) spheroids, labeled with α-Ki67 antibody (green), indicating cell proliferation and the DNA dye Hoechst 33,342 (blue). Scale bars, 200 μm.

(B–E) (B) Percentage of HIF1α-positive, (C) cleaved caspase-3-positive, and (D) CD133-positive cells as determined by FACS. (In B–D, n = 3, unpaired t test; n.s.). (E) Lattice light-sheet images of a bioprinted spheroid, stained with phalloidin-568 (red) and SYTOX green (blue). The images were further sliced at 34.95 μm (E1), 27.45 μm (E2), and 19.95 μm (E3) from the top to show the high-resolution cellular arrangement of the spheroids. Scale bars, 10 μm.

(F) Quantification of the cell-cell density was conducted by measuring the average distance between the nearest-neighboring nuclei in 3 dimensions for both manually prepared and 3D bioprinted SK-N-BE(2) spheroids (n = 3).

Results are means ± SEM. See also Figures S3–S5.