Fig. 3

Illustration of the advantages of hydrogels as wound dressings. a Images demonstrating adhesion of bioglass (BG)/oxidized sodium alginate (OSA) hydrogel to bone, liver, fat, skin, muscle and cardiac tissue. Reproduced with permission [75]. Copyright 2019, Springer Nature. b Equilibrium PBS content of hydrogel. c Water vapor loss of hydrogels in a water-rich environment. d The remaining weight of the hydrogel during evaporation. Reproduced with permission [77]. Copyright 2005, Elsevier BV. e Diagram of a hydrogel with a 3D structure used to load drugs and achieve controlled drug release in response to external stimuli. Reproduced with permission [78]. Copyright 2015, American Chemical Society. Release kinetics of DS (f) and MF (g) in pH/ROS responsive hydrogel (DS%MIC@MF) under different conditions. Reproduced with permission [83]. Copyright 2022, Elsevier. h–j Cold resistance of smart hydrogel. h Hydrogel H-G60 was successively stored at low temperature and room temperature for 2 h of stress, and was subjected to 10 cyclic stress treatments under the same conditions. i Freeze–thaw cycle curve of H-G60 at − 20 °C. j The hydrogel is connected to the circuit at − 20 °C for 2 h and the light emitting diode (LED) bulb is very bright. Reproduced with permission [84]. Copyright 2022, American Chemical Society. 3D three dimensions, DS diclofenac sodium, MF mangiferin