From flow to form: structuring and patterning hydrogels using microfluidic approaches

Three-dimensional (3D) cell culture can leverage the precise arrangement of materials, known as patterning, to generate physiologically relevant tissue-like structures. Hydrogels are widely used in 3D cell culture due to their ability to mimic the properties of biological extracellular matrix networks. In this tutorial review, we discuss the use of microfluidic systems to control fluid movement and placement within fabricated microchannels to pattern hydrogel precursors in 3D through the use of capillary flow. Such systems offer unique advantages in their ability to create complex biomimetic structures, organs-on-a-chip, and microphysiological systems with high spatial resolution and relatively small volumes of hydrogel material. We first discuss the fundamental principles behind capillary pinning and aspiration-mediated patterning. We then review literature describing the development an…