*2.9. ICD Assay*

B16F10 cells were incubated in 6-well plates (3 <sup>×</sup> <sup>10</sup>5/well) for 12 h, with 3 mL complete medium in each well. Then, 300 µL mPEG-PELG hydrogel loaded with Dox (5 µg/mL) was added and incubated for another 4 h. The same dose of Dox solution was used as the positive control. After digestion with 1 mL trypsin, the cells were harvested and washed, and incubated with 100 µL PBS plus 2 µL Alexa Fluor® 488 calreticulin polyclonal antibody solution (Abcam, Cambridge, UK) for 1 h. Finally, the treated cells were detected and analyzed by flow cytometry (BD FASCCelestaTM Flow Cytometer, BD Biosciences, San Jose, CA, USA).
