(549g) 3D-Printed Models of Organ Development (INVITED SPEAKER)

The development of most organs requires concerted and reciprocal interactions between an epithelial sheet or tube and its surrounding mesenchyme or stroma. Guidance cues in the form of morphogen gradients or aligned fibers of extracellular matrix proteins have been posited to provide directional information that templates the pattern of morphogenesis of the epithelial tissue. For example, the ductal tree of the mammary gland forms stochastically, but with a characteristic bias that has been assumed to result from aligned fibers of collagen within the fatty stroma. To test whether such physical scaffolding can account for the pattern of mammary branching, we carried out quantitative imaging analysis to characterize the 3D architecture of the organ as a function of developmental time. We then used 3D-printing approaches to generate the adipose stroma and collagen-fiber alignment patterns that we found in vivo, and investigated the pattern of epithelial branching that resulted from varying these geometric features. Here, I will describe our imaging and 3D-templating pipelines, discuss how this combination has led to new insights in tissue development, and generalize our findings to future efforts in quantitative developmental biology and tissue engineering.