Gelatin-Sodium Alginate Hydrogel Processing by Low-Temperature 3D Printing

Hydrogel materials and forming processes have a significant impact on the performance of tissue engineering scaffolds and cell 3D printing. Scaffolds supports cell adhesion as a temporary extracellular matrix, which plays a key role in tissue engineering and regenerative medicine. Hydrogel 3D structure bio-fabrication was an important step towards cell 3D printing. A precision extrusion nozzle based on ball screw transmission was developed for porous hydrogel fabrication. The whole bio-fabrication temperature was controlled between 4-14°C which eliminates ice exactly. Three-dimensional structure was formed based on the temperature-sensitive gelling properties of gelatin. Hereby, the influence of hydrogel concentration, extrusion speed and scanning speed, printing temperature, scanning spacing and the heights of layer were analyzed in depth. Hydrogel scaffolds were fabricated pore network in the gelatin 10% and the sodium alginate 2%. The processing parameters of this paper can be directly applied to hybrid printing of cell and hydrogel material.