3D cell/scaffold model based on aligned-electrospun-nanofiber film/hydrogel multilayers for construction of anisotropic engineered tissue

Many tissues have a three-dimensional (3D) anisotropic structure compatible with their physiological functions. Engineering an in vitro 3D tissue having the natural structure and functions is a hotspot in tissue engineering with application for tissue regeneration, drug screening, and disease modeling. Despite various designs that have successfully guided the cellular alignment, only a few of them could precisely control the orientation of each layer in a multilayered construct or achieve adequate cell contact between layers. This study proposed a design of a multilayered 3D cell/scaffold model, that is, the cell-loaded aligned nanofiber film/hydrogel (ANF/Gel) model. The characterizations of the 3D cell-loaded ANF/Gel model in terms of design, construction, morphology, and cell behavior were systematically studied. The ANF was produced by efficiently aligned electrospinning using a self-designed, fast-and-easy collector, which was designed based on the parallel electrodes and modified with a larger gap area up to about 100 cm2. The nanofibers generated by this simple device presented numerous features like high orientation, uniformity in fiber diameter, and thinness. The ANF/Gel-based cell/scaffold model was formed by encapsulating cell-loaded multilayered poly(lactic-co-glycolic acid)-ANFs in hydrogel. Cells within the ANF/Gel model showed high viability and displayed aligned orientation and elongation in accordance with the nanofiber orientation in each film, forming a multilayered tissue having a layer spacing of 60 μm. This study provides a multilayered 3D cell/scaffold model for the in vitro construction of anisotropic engineered tissues, exhibiting potential applications in cardiac tissue engineering.