Characterization of UV-crosslinked hydrogels for 3D bioprinting

Abstract

3D bioprinting technology is considered as a giant advancement towards biomedical applications, namely cell and tissue engineering. A major challenge is to fabricate suitable hydrogels for bioink usage. In this study, different concentration ratio of Gelatin Methacrylate (GelMA) and Pluronic-monocarboxylate (PluMP) are mixed to fabricate UV-crosslinked hydrogel for 3D bioprinting using extrusion bioprinter. Characterisation of its properties will also be executed for tissue engineering applications. For the experiments, GelMA and PluMP are mixed in mass ratios of 2:1, 1.5:1, 1:1, 1:1.5, and 1:2. Layer by layer printing of the hydrogels are performed using multi-nozzle extrusion based 3D bioprinter. By observing the stability and height of the printed construct, we can conclude that the 1:2 sample possessed excellent printability. For FTIR, the samples produced similar chemical fingerprints. The 1:2 sample also displayed high surface porosity from SEM experiment. Next, the swelling ratio and water content of each concentration ratio can be calculated through the swelling test. By immersing all 5 samples in water and weighing them before and after the swelling process, we can conclude that the 1:2 sample has the best swelling ability which is important for nutrient absorbance when fabricating tissue scaffold. Lastly, for mechanical testing, the samples were printed into 3D dogbone and circular shaped for tensile and compression test respectively. From this experiment, we are able to determine mechanical properties such as average modulus for both tensile and compression and concluded that the 2:1 sample possessed the highest mechanical strength. Therefore, by varying the GelMA concentrations, we are able to formulate a material most suited for fabrication of tissue engineering scaffold.