Customized construction of microscale multi-component biostructures for cellular applications

In vitro biofabrication is employed in fields such as biomedicine and those using biomimetic materials. However, it suffers from drawbacks such as low resolution, applicability on a limited range of components, and difficulty in purposefully depositing specific cells in three-dimensional space. Hence, this paper proposes a digital micromirror device-based optical projection lithography (DOPL) system for producing multi-component microstructures with resolutions of tens of microns and explores the behavior of cells with these structures. The printability and mechanical properties of these microstructures were investigated to assess their reproduction quality and the ability to control their structural characteristics. The results show that when DOPL is used with polyethylene glycol dimethacrylate (PEGDMA) hydrogel, an array of micropits can be fabricated within a few minutes. Furthermore, uniform cell spheroids form rapidly with high throughput when they are seeded into the micropits. Additionally, PEGDMA and gelatin methacryloyl (GelMA) were used to construct multi-component microstructures, and it was demonstrated that cells with various morphologies selectively adhere to the heterogeneous interface. In addition, DOPL could enable deposition of various cells for constructing microenvironments and for drug screening. Finally, a biomimetic peritoneal model was constructed. Overall, this work demonstrates the versatility of this system and its potential in cellular applications such as cell behavior research, drug screening, and tissue engineering.