서강대학교

초록 (요약문)

3D bio-printed scaffolds have been reported as superior candidates for tissue engineering for their ability to create complex structures with high accuracy and reproducibility. There are still remaining challenges in fabricating functional scaffolds with precise gradient architectures. We developed a bioprinting technique that is capable of printing 3D step-gradient hydrogels without continuous gradient regions at the interfaces. First, we designed a single nozzle active mixing based on-the-fly refueling printhead for the extrusion of biopolymer inks in low Reynolds numbers. To test the functional gradient of hydrogel, a human ear cartilage model was fabricated with resin composed of GelMA, sodium alginate, and polyethylene glycol diacrylate (PEGDA) where the local elasticity of the hydrogel was controlled by altering the concentration of PEGDA from 0%v/v to 10%v/v. The printed ear cartilage scaffold showed an elasticity difference from 9.37 to 120 kPa depending on PEGDA concentrations. Moreover, SEM analysis on the interfaces of the gradient scaffold clearly shows the pore size difference depending on the compositional change: 5-9 μm for the non-PEGDA phase and 3-5 μm for PEGDA (10%)-containing phase.