Preparation and rheological characterization of cellulose-chitosan hydrogel for extrusion 3d printer

The application of three-dimensional (3D) printing in tissue engineering is becoming prominent nowadays. A big obstacle for this technology is the selection of proper ink material. Chitosan hydrogel is an established biocompatible material that can be used as tissue scaffolds, and it has the rheology necessary for processing via extrusion type 3D printer. However, chitosan still has degradation and swelling limitations. Hence, chitosan hydrogel blends were incorporated with cellulose particles and were prepared as ink material. The hydrogels were successfully synthesized via thermo-responsive sol-gel method. Fourier transform infrared spectroscopy (FT-IR) analysis showed that the gelation of hydrogels formed a semi-interpenetrating network of ionically crosslinked chitosan and cellulose particles. Rheological tests have shown that the hydrogels exhibited shear thinning property necessary for printing. However, high cellulose amounts caused clogging during printing, and the presence of water limited the structural rigidity of the printed product. Besides this, it was found that the addition of cellulose was able to increase swelling, decrease degradation rate, and decrease gelation time, but the effect is not significant for any of these three properties.