ABSTRACT
Nowadays, therapies for regenerating damaged biological tissues or organs attract more and more attentions. Scaffolds with increasing complexity and sophistication are widely used to serve as engineered extracellular matrix (ECM). The ECM is a non-cellular material, and a complex network of chemically different macromolecules that offers not only structural/mechanical support, but also essential chemical and physical guidance cues for cells. This chapter demonstrates a method that involves an engineered composite hydrogel structure including the stiffness interfaces inside it and steep gradient of cell concentration around the stiffness interfaces to serve as the 3D culture matrix for inducing the formation of 3D multicellular structures. Confocal laser-scanning microscopy revealed that the straight multicellular tubes are always parallel to the vertical interfacial plane inside the composite gel, and it has continuous lumen.
