Research on 3-D Bio-printing Molding Technology of Tissue Engineering Scaffold by Nanocellulose/gelatin Hydrogel Composite

In the biomedicine field, three-dimensional (3-D) printing of biomaterials can construct complex 3-D biological structures such as personalized implants, biodegradable tissue scaffolds, artificial organs, etc. Therefore, nanocellulose/gelatin composite hydrogels are often selected as bio-printing materials in the 3-D printing of biological scaffolds. Process parameters of 3-D printed bio-scaffolds were studied in this work because formation accuracy of scaffolds is an important part of the molding process. Firstly, the mixing proportion of nanocellulose and gelatin was explored, and the optimum proportion was selected. Then, the printing effects of different printing pressures, temperatures, speeds, and nozzle diameters were used in the 3-D printing. The filament widths were used to evaluate the molding effects. Finally, through the calculation and analysis of the grey correlation coefficient and grey correlation degree, the multi-objective optimization of the parameters was carried out. The combined effects of the process parameters and the influence degree order on the evaluation index were obtained. Using these parameters, the 3-D porous biological scaffolds were printed with high precision. Furthermore, using a microscope, the morphologies of CCK-8 cells were observed and the cell proliferation were analyzed. The results demonstrated that the printed bio-scaffolds had good biocompatibility.