Representative images of constructs printed using 15% GelMA bioink: (A) A phase contrast image of a CMC-laden construct, (B) LIVE/DEAD labeling of a freshly printed CMC construct showing diffuse GelMA staining, live cells in green and dead cells in red (arrows), (C) illustrative phase contrast image of a 3D construct with encapsulated CMC cells, (D) illustrative phase contrast image of a 3D construct with interconnected CFB cells, (E) LIVE/DEAD staining of a 7-day, CFB-laden construct showing abundance of interconnected live cells (green) and nuclei of dead cells (red), (F) a close-up of the same construct, (G) CMCs within 7-day old construct stained for actin (phalloidin, red) and nuclei (DAPI, blue), and (H) CFBs within 7-day old CFB-laden construct stained for actin (phalloidin, red) and nuclei (DAPI, blue).
CFB: Cardiac fibroblast; CMC: Cardiac myocyte; GelMA: Gelatin methacryloyl; LDH: Lactate dehydrogenase.