DSC was performed using a DSC Q20 (TA instrument) equipped with Universal Analysis 2000 software. Approximately 5 mg of chitosan powder was weighed and sealed in aluminium pans using a Tzero Sample Press Kit. An empty pan was used as reference. The samples were subjected to two heating/cooling cycles and a final heat ramp. In the first cycle for chitosan powder and hydrogels, the samples were heated from -50°C to 200°C and cooled to -50°C. In the second cycle, the samples were heated from -50°C to 500°C and immediately cooled down to -50°C. The final cycle consisted of a single heat ramp from -50°C to 500°C. All temperature ramps had a heating/cooling rate of 10°C/min under constant purging of dry nitrogen at 50 ml/min.