Fig. 8

Preparation and evaluation of 3D human EHTs using KCNJ2 OE iPSC-CMs. a Process of decellularization of rat hearts and preparation of natural heart extracellular matrix (ECM). b Major ECM compositions (laminin, fibronectin and collagen III) of decellularized hearts and native rat hearts detected by immunofluorescence staining. Fluorescent detection was assessed with a confocal microscope (Leica TCS-SP8). Scale bar, 200 μm. c Schematic diagram of the preparation of 3D human engineered human heart tissues (EHTs) with or without KCNJ2 OE. This image was drawn by the authors. Double immunofluorescence staining for TNNT2/α-smooth muscle actin (α-SMA) (d), TNNT2/von Willebrand factor (vWF) (e), and TNNT2/connexin 43 (CX43) (f) in the EHTs. The right panels showed a higher magnification image of the boxed region in the left panel. Fluorescent detection was assessed with a confocal microscope (Leica TCS-SP8). Scale bars, 20 μm. g Quantification of the α-SMA+, vWF+ and CX43+ structures in the EHTs with or without KCNJ2 OE. n = 8 views.