2.7. Compressive properties
Hydrogel dressings were prepared in an injector using the mixture of solutions above to form columned hydrogels (15 mm diameter, 10 mm height). The stress-strain curves of hydrogels were determined using a Universal Testing Machine (Instron 5943, USA) at a constant displacement rate loading of 1 mm/min to the stress reached the yield point. Compressive moduli of samples were calculated from the stress-strain curves.