Abstract
Anisotropic microstructures resulting from a well-ordered arrangement of filamentous extracellular matrix (ECM) components or cells can be found throughout the human body, including skeletal muscle, corneal stroma, and meniscus, which play a crucial role in carrying out specialized physiological functions. At present, due to the isotropic characteristics of conventional hydrogels, the construction of freeform cell-laden anisotropic structures with high-bioactive hydrogels is still a great challenge. Here, we proposed a method for direct embedded 3D cell-printing of freeform anisotropic structure with shear-oriented bioink (GelMA/PEO). This study focuses on the establishment of an anisotropic embedded 3D bioprinting system, which effectively utilizes the shear stress generated during the extrusion process to create cells encapsulating tissues with distinct anisotropy. In conjunction with the water-solubility of PEO and the in-situ encapsulation effect provided by the carrageenan support bath, high-precise cell-laden bioprinting of intricate anisotropic and porous bionic artificial tissues can be effectively implemented in one-step. Additionally, anisotropic permeable blood vessel has been taken as a representation to validate the effectiveness of the shear-oriented bioink system in fabricating intricate structures with distinct directional characteristics. Lastly, the successful preparation of muscle patches with anisotropic properties and their guiding role for cell cytoskeleton extension have provided a significant research foundation for the application of the anisotropic embedded 3D bioprinting system in the ex-vivo production and in-vivo application of anisotropic artificial tissues.