Flexible Fabrication of Shape-Controlled Collagen Building Blocks for Self-Assembly of 3D Microtissues

creating artificial tissue-like structures that possess the functionality, specificity, and architecture of native tissues remains a big challenge. a new and straightforward strategy for generating shape-controlled collagen building blocks with a well-defined architecture is presented, which can be used for self-assembly of complex 3d microtissues. collagen blocks with tunable geometries are controllably produced and released via a membrane-templated microdevice. the formation of functional microtissues by embedding tissue-specific cells into collagen blocks with expression of specific proteins is described. the spontaneous self-assembly of cell-laden collagen blocks into organized tissue constructs with predetermined configurations is demonstrated, which are largely driven by the synergistic effects of cell-cell and cell-matrix interactions. this new strategy would open up new avenues for the study of tissue/organ morphogenesis, and tissue engineering applications.