Bio-Inspired Screwed Conduits from the Microfluidic Rope-Coiling Effect for Microvessels and Bronchioles

Tubular microfibers have recently attracted extensive interest for applications in tissue engineering. However, the fabrication of tubular fibers with intricate hierarchical structures remains a major challenge. Here, we present a novel one-step microfluidic spinning method to generate bio-inspired screwed conduits (BSCs). Based on the microfluidic rope-coiling effect, a viscous hydrogel precursor is first curved into a helix stream in the channel, and then consecutively packed as a hollow structured stream and gelated into a screwed conduit (SC) via ionic and covalent crosslinking. By taking advantage of the excellent fluid-controlling ability of microfluidics, various tubes with diverse structures are fabricated via simple control over fluid velocities and multiple microfluidic device designs. The perfusability and permeability results, as well as the encapsulation and culture of human umbilical vein endothelial cells (HUVECs), human pulmonary alveolar epithelial cells (HPAs), and myogenic cells (C2C12), demonstrate that these SCs have good perfusability and permeability and the ability to induce the formation of functional biostructures. These features support the uniqueness and potential applications of these BSCs as biomimetic blood vessels and bronchiole tissues in combination with tissue microstructures, with likely application possibilities in biomedical engineering.