[2] Hydrogel dressings can be designed to prevent bacterial infection, retain moisture, promote optimum adhesion to tissues, and satisfy the basic requirements of biocompatibility.
[1][5] Hydrogel dressings should possess mechanical and physical properties similar to the 3D microenvironment of the extracellular matrix of human skin.
[citation needed] Synthetic dressings incorporating nanoparticles such as PVA and polyethylene glycol (PEG) are assembled using chemical cross-linking mechanisms.
[citation needed] Physically cross-linked hydrogels disintegrate due to local changes in pH, ionic strength, and temperature.
[citation needed] Hydrogels used in wound dressings can be self-assembled upon addition of divalent metal cations or electrically charged polysaccharides due to electrostatic interactions.
[8][12] Cross-linking of soluble hydrophilic monomers forms a 3D insoluble netted structure which can incorporate a large amount of water.
[15][20] Hydrogel dressings can adhere directly to the wound bed under normal physiological conditions via oxidation-reduction reactions of quinones.
[2][21] The adhesive properties of hydrogels have been shown to be enhanced by addition of positively charged microgels (MR) into the 3D matrix to increase electrostatic and hydrophobic interactions.
Hai Lei et al. demonstrated that poor elasticity and hysteresis in naturally-derived protein-based hydrogels can be remedied by the addition of polyprotein cross-linkers.
[22][24] Hydrogel dressings mimic the fibrous nature of native ECM to maintain cell-to-cell communication at the wound bed for tissue regeneration.
[39][40][41] Other studies have shown that hydrogel dressings accelerate healing in radioactive skin injuries and dog bite wounds.
[42][43][44] Hydrogel dressings decrease the healing time of traumatic skin injuries by an average 5.28 days and reduce the pain reported by patients.
[55][56] Hydrogels may be modified to incorporate metal cations (e.g. copper (II)), degradable linkers (e.g. dextran), and adhesive functional groups (e.g.