Fig. 4.

Full-fledged and high-resolution cardiac structures engineered by advanced 3D bioprinting. Through accurate printing and cross-linking of cell-loading cardiac bioink, the original structure of heart can be realistically reproduced in construction of: linear columnar (A) [85], grid-like pattern (B) [67], spherical cluster (C) [148], rectangular parallelepiped (D) [86], valentine heart-shaped material (E) [72], cube-shaped block (F) [71], perforated column (G) [84], conical container (H) [102], four-chamber sagittal plane (I) [102], heart valve-like structure (J & K) [68,102], left heart with large vessel-like construction (L) [68], right ventricle-like construction (M & N) [90], and micro vascularized HEHT (O) [117].