Effect of gelatin concentration on the mechanical properties and in vitro degradation behaviour of gelatin/carboxymethyl cellulose-based 3D printed scaffolds

In this study, gelatin (Gel)-carboxymethyl cellulose(CMC)-based tissue scaffolds were prepared by using extrusion-based 3D printing in four formulations named as 7.5G, 10G, 12.5G, and 15G. The prepared inks were characterized with rheological study and the printed scaffolds were analyzed in terms of their Fourier transformed infrared spectroscopy (FTIR), mechanical study, swelling, degradation and contact angle measurements. The rheological results showed that the increase in Gel concentration resulted in higher viscosity values, printing temperature and pressure, primarily due to the enhanced electrostatic interactions between Gel and CMC. According to the mechanical test results, gelatin concentration had significantly effects on the elastic modulus and strain (%) and suitable for soft tissue engineering applications. Furthermore, as the amount of Gel increased, the tissue scaffolds swelled less, and 15G had the lowest swelling ratio due to the most covalent crosslinking. Gel-CMC hydrogels are promising ink candidates for 3D printing for tissue engineering applications.