A soft receiving platform for coaxial bioprinting cell-laden microtubes with uniform wall thickness

Coaxial bioprinting can fabricate cell-laden microtubes with high precision and efficiency. However, strands extruded from coaxial nozzles often flatten upon contacting conventional receiving platforms made of hard materials, such as glass or metal, resulting in nonuniform wall thickness in microtubes. Therefore, a soft receiving platform made of soft materials for coaxial bioprinting was designed in this study. The deformation of strands was reduced when they were extruded onto the soft receiving platforms. Straight microtubes with uniform wall thickness and multi-layer stable scaffolds were fabricated when using soft receiving platforms made of 6 wt% alginate solution. The microtubes printed on soft receiving platforms exhibited good perfusion ability and increased burst pressure. Finally, L929 cells encapsulated in the biomaterials were coaxial printed onto the soft receiving platforms. The cells showed good viability and proliferation after being cultured for 7 days. These results demonstrate that the soft receiving platforms proposed in this study can fabricate cell-laden microtubes with uniform wall thickness, which facilitates the fabrication of vascular structures for tissue engineering.