Figure 7. TGF-β1 induces pro-fibrotic changes, such as increased contractility of hydrogels, increased mechanical stiffness, and asynchronous beating, in 3D engineered cardiac tissues.

A) Beating patterns of 3D engineered cardiac tissues cultured in NM (green) and NM + TGF-㬡1 (red) at day 7, 9, 11, and 13. The three red lines (solid and 3dotted) represent three independently areas of beating within the same area of view. B) Hydrogel contraction test. Optical images of TGF-㬡1 treated and non-treated hydrogels with encapsulated cardiomyocytes and cardiac fibroblasts. C) Quantitative analysis of the contraction test of cardiomyocytes/cardiac fibroblast encapsulated GelMA hydrogels in NM compared to NM + TGF-㬡1. D) Representative scanning electron microscopy images of cell (white arrows)-encapsulated GelMA hydrogels cultured in NM and NM + TGF-㬡1 on day 14 of culture. E) Mechanical stiffness of the 3D cardiac tissues in the two different culture conditions (NM and NM+TGF-㬡1) at day 14 of culture. Data depict Mean ± Standard deviation. *p<0.05