Enhancement of cell viability by fabrication of macroscopic 3D hydrogel scaffolds using an innovative cell-dispensing technique supplemented by preosteoblast-laden micro-beads

• We propose a new cell-encapsulated dispensing method.
• Fabrication was conducted using a three-axis robot system and an aerosol-spraying method.
• The scaffold shows a realistic macroscopic pore-size and 100% pore-interconnected structure.
• The use of micro-sized beads containing cells enhances cell viability in the dispensed 3D structure.

We propose a new cell-encapsulated dispensing method consisting of hydrogel struts, embedded with cell-laden micro-beads. To develop the scaffolds, we accommodated a three-axis robot dispensing system and aerosol spraying of a cross-linking agent to effect tentative surface gelation of hydrogel alginate struts. To show the feasibility of the method, we used pre-osteoblast (MC3T3-E1) cells. Using this technique, we obtained a reasonable cell viability (>90% after several culture periods) relative to that of a scaffold onto which cells were dispensed in the conventional manner, and successfully fabricated a realistic macroscopic pore-size in a controlled manner with 100% pore-interconnected 3D alginate hydrogel scaffolds of 20 mm × 20 mm × 6 mm.