Injectability and shear-thinning properties of collagen furan hydrogel. To evaluate the injectability and shear-thinning properties of hydrogels, all components of r2 hydrogel were mixed in the syringe mixing system, and the crosslinking reaction was allowed to proceed in the syringe for different period of time (0h, 4h, and 48h), followed by extrusion through a 27 G needle from the syringe onto the rheometer plate. Afterward, viscosity under continuous shear was measured with increasing the shear rate from 0.01 to 100 s -1 as shown in Figure .