One Step Formation of Heterogeneous Tubular Biomaterials and Stimulus Responsive Hydrogels

Tubular structures are fundamental constituents of plant, animal and human tissues. Synthetically prepared biomaterial tubular constructs have a variety of applications that include engineered blood vessels, vascularized biomaterials as well as soft robotic actuators. Currently there is no one-step method for the scalable preparation of perfusable tubular soft materials that allows the tube size, morphology, composition and tensile properties to be consistently altered. We report a scalable microfluidic approach for the consistent formation of cross-linked biopolymer tubes in sodium alginate and collagen I, with outer diameters between 0.7 mm and 2.5 mm, at extrusion velocities between 1mm/s and 20mm/s. We report the consistent formation of homogeneous tubes with cylindrical, crimped, and corkscrew inner wall surfaces. Heterotypic tubular constructs possess up to three concentric wall layers, or consist of single-layered "Janus" tubes and tubes with incorporated axial stripe patterns. Fluorescent microspheres and swelling nanoparticles were incorporated as payload and allowed us to image the tube architecture and induce predictive shape transformations. This research can potentially lead to high throughput construction of complex spatially organized 3D functional soft materials and tissues.M.A.S