Fig 1.
Fibronectin (FN)-gelatin (G)-coated human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) had improved tolerance to hypoxia.
(A) Schematic illustration of layer-by-layer filtration for nanofilm coating with FN and G on cell surfaces. (B) Lactate dehydrogenase production (LDH) assay. (C) Cell survival using Cell Counting Kit-8. (D) The beating area of cells assessed by Cell Motion Imaging System. * P < 0.01, ** P < 0.001.
Fig 2.
Transplantation of three-dimensional human induced pluripotent stem cell-derived cardiac tissue (3D-hiPSC-CT) to the infarcted rat heart.
(A) Schematic illustration of construction of 3D-hiPSC-CT by the cell accumulation technique. (B) Hematoxylin and eosin (HE) staining image of 3D-hiPSC-CTs; scale bar = 100 μm. (C) Implantation of 3D-hiPSC-CT to the heart surface at the infarction site. (D) Left ventricular histology assessed 4 weeks after transplantation with HE staining. (E) Engraftment of 3D-hiPSC-CT to the heart surface at the infarction site; scale bar = 100 μm. Dashed yellow lines represent the areas of transplanted 3D-hiPSC-CT.
Fig 3.
The three-dimensional human induced pluripotent cell-derived cardiac tissue (3D-hiPSC-CT) improved cardiac function in the myocardial infarction rat model.
(A–C) Results of B-mode echocardiogram: left ventricular ejection fraction (LVEF), end-diastolic diameter (LVDd), and end-systolic diameter (LVDs); *P < 0.01, ** P < 0.001. (D) Fibrosis area at the remote zone in myocardial infarction hearts 4 weeks after transplantation. Sections were assessed by Picro Sirius Red staining. * P < 0.01.
Fig 4.
The three-dimensional human induced pluripotent stem cell-derived cardiac tissue (3D-hiPSC-CT) induced angiogenesis and angiogenic cytokine expression in the peri-infarct zone.
(A) Capillary density in the peri-infarct zone in the myocardial infarction rat heart 4 weeks after transplantation; scale bar = 100 μm. Sections were assessed by immunohistochemical staining for von Willebrand factor; * P < 0.01. (B) Immunostaining for isolectin B4 (white), TnT (green), human nuclei (red), and DAPI (blue); scale bar = 50 μm. (C) Quantitative polymerase chain reaction analysis of angiogenic cytokine-related gene expression (Vegf and Hgf: * P < 0.01.
Fig 5.
Ultrastructural analysis of 3D-hiPSC-CT using transmission electron microscopy (TEM).
(A) TEM images of 3D-hiPSC-CT in vitro. The hiPSC-CM (CM) are assembled to be in contact with each other via desmosomes (white arrow). A few myofibrils (mf) and mitochondria (m) are observed within the cardiomyocytes, scale bar = 1 μm. (B) TEM images of 3D-hiPSC-CT in vivo. The 3D-hiPS-CT showed clear thickened myofibrils (mf), Z-band (Z), and mitochondria (m). The adherens junction (black arrow) and desmosome (white arrow) were also disclosed between the iPSC-CM, scale bar = 1 μm.
Fig 6.
Implantation of three-dimensional human induced pluripotent stem cell-derived cardiac tissue (3D-hiPSC-CT) promoted extracellular matrix (ECM) remodeling and maturation of cardiomyocytes.
(A-1) Immunostaining of fibronectin (green) on 3D-hiPSC-CT in vitro. (A-2) Fibronectin expression (green) was poor in the cardiac tissue 12 weeks after transplantation. (B-1) Immunostaining of collagen IV (green) on the 3D-hiPSC-CT in vitro. (B-2) Collagen type IV (green) was clearly expressed in the transplanted tissue 12 weeks after implantation. (C-1) Immunostaining of perlcan (green) was not observed on the 3D-hiPSC-CT in vitro. (C-2) Perlcan (green) was clearly expressed in the transplanted tissue 12 weeks after implantation. (D-1) Immunostaining of desmin (green) was not observed on the 3D-hiPSC-CT in vitro. (D-2) Desmin (green) was expressed in the transplanted tissue. (E-1) Immunostaining of dystrophin (green) was not observed on the 3D-hiPSC-CT in vitro. (E-2) Dystrophin (green) was clearly expressed in the transplanted tissue. (F-1) The expression of connexin43 (green) was poor on the 3D-hiPSC-CT in vitro. (F-2) Connexin43 (green) was clearly expressed in the transplanted tissue 12 weeks after implantation.