(175at) Coaxial 3D Bioprinting of Hydrogels with Small Diameters to Mimic Microvasculature

Coaxial bioprinting is explored to print tubular structures, which is especially useful for printing organs with vasculature so that they could be similar to how the organs operate within the human body. However, one issue is that due to the varying sizes of blood vessels, not everything is easily replicable, especially at reduced diameters. Most commercially available coaxial nozzles allow printing tubular structures as low as 200 µm, which is still much higher than the lowest limits of blood vessels.

In this work, we have custom built a nozzle that could provide hollow tubular structures with inner diameters less than 100 μm, allowing us to achieve vasculature using a chitosan-gelatin thermosensitive hydrogel in combination with poloxamer. Using much simpler procedure of varying the inner and the outer flow rates, we can vary the tube diameters. Cell culture work demonstrates feasibility of printing cell-laden structures and scaling to include multiple cell types.