Three-Dimensional Cell Sheet Construction Method with a Polyester Micromesh Sheet

Cell sheet engineering has become important in a variety of fields, including regenerative medicine and transplantation. Our research group previously developed micromesh cultures that enable cells to form a cell sheet on a microstructured mesh sheet. Here, we present a more usable micromesh culture and devices that make it possible, aiming for widespread use. The devices are mainly constituted of a polyester micromesh sheet and three-dimensional (3D)-printed simple frames that fix the mesh sheet on it. Cells such as fibroblast Tig-1-20 cells, hepatoma HepG2 cells, or mesenchymal stem cells (MSC) were easily seeded on the polyester mesh sheet in the device and cultured for 16 days, which was followed by the formation of a 100-400-μm-thick cell sheet. The cell sheet was very robust, easy to handle, and could be readily removed from the device for subsequent analysis. Optical coherence tomography revealed the structure of the cell sheet as having the mesh sheet layer in the center of the cell sheet. Confocal microscopy demonstrated that Tig-1-20 cells in the cell sheet were aligned according to the shape of the mesh apertures, indicating that cell orientation can be controlled with this micromesh culture. As for another application, the device was used to construct a multilayered cell sheet that consists of three different types of cells. Furthermore, for mass production, the device frames were made using polyoxymethylene (POM) instead of 3D printing materials. Using the POM devices, a large MSC sheet for 10 cm dishes was successfully produced 7 days after cell seeding. This micromesh culture may become one of the useful cell sheet construction methods in future for medical and research fields. Impact statement Currently, cell sheets are constructed, for example, on a temperature-responsive polymer-coated dish or a porous membrane. These cell sheets are widely used but are not completely suitable in terms of robustness, ease of handling, cost, ease of microscopic cell observation, or nutrient supply. We previously reported that the micromesh culture can provide a three-dimensional (3D) cell sheet that has advantages for cell observation and nutrient supply. In this study, the micromesh culture was enhanced with a polyester micromesh sheet and a series of devices of polyoxymethylene, helping us to produce a robust, cost-effective, easily layered, and easy-to-use 3D cell sheet.