Multi-material 3D Bioprinting of Complex Heterogeneous Constructs for In-vitro Mechanobiology Studies

Résumé fourni par la source

Multi-material bioprinting is a technology that enables the fabrication of complex, heterogeneous and/or multicellular constructs that can mimic the microenvironment of living tissues. These constructs can be used as models for in-vitro studies of stiffness-dependent cellular behavior, becoming highly relevant on disease states such as cancer or fibrosis, a disease where progressive tissue stiffening drives fibroblast activation, migration, and proliferation. In this study, PEGDA and GelMA-based biomaterial inks with varying polymer concentrations were used to demonstrate direct 3D bioprinting of double and triple-material constructs with defined soft, stiff, and/or extra stiff regions. Geometrically complex structures, including meshes, and cylinders were printed to show the versatility and precision of using these inks to create multi-material heterogeneous constructs with defined regions of stiffness. By having precise control over stiffness placement, these constructs provide a useful tool for studying how mechanical differences affect cellular behavior in a heterogeneous environment. As proof of concept of the use of these materials for mechanobiology studies, human lung fibroblasts (HLFs) were cultured on top of 3D printed constructs containing regions with three different stiffnesses. The results showed an increase in fibroblast activation with stiffness, characterized by α-SMA expression, F-actin organization, and increased cell density. When compared to single-material systems, multi-material constructs showed differences in fibroblast response across stiffnesses, highlighting the impact of mechanical heterogeneity in diseased tissue. This shows the potential of multi-material 3D bioprinting to address limitations of traditional single-material systems by providing a platform for modeling stiffness-dependent diseases, exploring cell-microenvironment interactions and advancing tissue engineering and regenerative medicine applications.