Interestingly, the variability of tubular organs derives from the
broad diversity of different strategies to form epithelial tubes during development [2]. This variability generates a remarkable structural and cellular diversity: different tube sizes, shapes, and
connecting patterns [2–4]. The establishment and control of a
correct tubular architecture are fundamental, not only for the
understanding of the development of organs but also because
many diseases are often related with the loss of any of these epithelial characteristics. For instance, in some cancers, cells undergo an
epithelial-to-mesenchymal transition (EMT) that causes loss of cell
adhesion and polarity markers, which results in the activation of
migratory phenotypes [5]. This loss of epithelial integrity is associated with tumor progression and poor prognosis [6] also leading
to invasion and metastasis [7]. Besides cancer, defects in epithelial
morphogenesis during development also lead to other diseases like
polycystic kidney disease, atherosclerotic heart disease, or faciogenital dysplasia, among others. Therefore, understanding how an
epithelium can self-organize and create a tube at a molecular level, is
paramount to develop new tools and strategies for diagnosis and
treatment.
The control of the cellular microenvironment allows a deeper
understanding of the different cellular mechanisms that underlie
cell–cell and cell–matrix interactions. In traditional 2D cultures,
cells are randomly seeded and lack a specific organization as they
are maintained on flat and homogeneous substrates. Major drawbacks of these adherent cultures are the difficulty to control environmental parameters as well as the impossibility to recapitulate
multicellular architectures, tissue–tissue interfaces, and the physicochemical microenvironment found in vivo. This absence of a
physiologically relevant cell conformation strongly impacts on cell
function and behavior. However, micropatterning technology
allows the mechanical interaction with the cells by controlling the
geometry of cell adhesion and substrate rigidity. Thus,
micropattern-based substrates have helped to gain insights into
how the extracellular environment influences processes such as
the orientation of the cell division, organelle positioning, cytoskeleton rearrangement, cell differentiation, and directionality of cell
migration and lumen formation among others [8–13].
In this chapter, we show that micropatterning technology can
be used to fabricate a system able to recapitulate epithelial tube
morphogenesis in vitro. As there is no universal solution to produce
micropatterns, a compromise between simplicity, reproducibility
and excellence of patterning, together with an appropriate optical
quality of the substrate has to be found for each specific application [14]. Each of the platforms presented in this chapter has
different features and serves different purposes as well as provides
different rigidity cues. However, all of the developed
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Minerva Bosch-Fortea and Fernando Martı ´n-Belmonte
broad diversity of different strategies to form epithelial tubes during development [2]. This variability generates a remarkable structural and cellular diversity: different tube sizes, shapes, and
connecting patterns [2–4]. The establishment and control of a
correct tubular architecture are fundamental, not only for the
understanding of the development of organs but also because
many diseases are often related with the loss of any of these epithelial characteristics. For instance, in some cancers, cells undergo an
epithelial-to-mesenchymal transition (EMT) that causes loss of cell
adhesion and polarity markers, which results in the activation of
migratory phenotypes [5]. This loss of epithelial integrity is associated with tumor progression and poor prognosis [6] also leading
to invasion and metastasis [7]. Besides cancer, defects in epithelial
morphogenesis during development also lead to other diseases like
polycystic kidney disease, atherosclerotic heart disease, or faciogenital dysplasia, among others. Therefore, understanding how an
epithelium can self-organize and create a tube at a molecular level, is
paramount to develop new tools and strategies for diagnosis and
treatment.
The control of the cellular microenvironment allows a deeper
understanding of the different cellular mechanisms that underlie
cell–cell and cell–matrix interactions. In traditional 2D cultures,
cells are randomly seeded and lack a specific organization as they
are maintained on flat and homogeneous substrates. Major drawbacks of these adherent cultures are the difficulty to control environmental parameters as well as the impossibility to recapitulate
multicellular architectures, tissue–tissue interfaces, and the physicochemical microenvironment found in vivo. This absence of a
physiologically relevant cell conformation strongly impacts on cell
function and behavior. However, micropatterning technology
allows the mechanical interaction with the cells by controlling the
geometry of cell adhesion and substrate rigidity. Thus,
micropattern-based substrates have helped to gain insights into
how the extracellular environment influences processes such as
the orientation of the cell division, organelle positioning, cytoskeleton rearrangement, cell differentiation, and directionality of cell
migration and lumen formation among others [8–13].
In this chapter, we show that micropatterning technology can
be used to fabricate a system able to recapitulate epithelial tube
morphogenesis in vitro. As there is no universal solution to produce
micropatterns, a compromise between simplicity, reproducibility
and excellence of patterning, together with an appropriate optical
quality of the substrate has to be found for each specific application [14]. Each of the platforms presented in this chapter has
different features and serves different purposes as well as provides
different rigidity cues. However, all of the developed
228
Minerva Bosch-Fortea and Fernando Martı ´n-Belmonte