Integrated vascular engineering: Vascularization of reconstructed tissue

In this chapter, we describe culture methods to construct microvascular networks as well as approaches to integrating capillary networks with 3D epithelial tissueengineered constructs. First, culture models of microvascular networks such as in vitro angiogenesis and vasculogenesis models are introduced. Using these culture models, the roles of endothelial cells (ECs), such as endothelial tip, stalk, and phalanx cells, are demonstrated. Additionally, regulatory factors, including both biochemical and biophysical factors, are discussed in the context of 3D capillary formation, including the process of vascular development, growth, and maturation. Next, we focus on the use of microfluidics technologies for investigating capillary morphogenesis. Examples of 3D capillary formation assays with growth factor gradients and different extracellular matrix materials are described. Cocultures of ECs and the other cell types in microfluidic devices are also introduced to show the potential of microfluidic vascular formation models. The vascularization of constructed tissues is discussed from the viewpoints of horizontal and vertical approaches for combining capillary structures and epithelial tissues in vitro. Finally, the concept of integrated vascular engineering and future perspectives are discussed.