Proanthocyanidin-Driven Multifunctional Injectable Hydrogel as an Effective Skin Dressing for Atopic Dermatitis.

Patients with atopic dermatitis (AD) often experience symptoms of skin dryness, coinfection, oxidative damage, immune dysfunction, and inflammatory response. Clinical recommendations typically include antibiotics, glucocorticoids, and immunosuppressants, but frequent use of these medications can lead to drug resistance and adverse side effects. Herein, a pH/ROS-responsive injectable dual network hydrogel (HCFP) was developed by cross-linking oxidized hyaluronic acid, quaternized chitosan, and proanthocyanidins (PA) for the treatment of atopic dermatitis (AD). The HCFP hydrogel exhibited robust adhesive and self-healing properties, preventing delamination by scratching while enhancing the penetration of PA into the stratum corneum. In vitro and in vivo studies showed that HCFP effectively restored the skin barrier, suppressed bacterial infection, alleviated oxidative stress, modulated the immune response, and reduced inflammation, outperforming clinical dexamethasone ointment. This multifunctional hydrogel, which combines antibacterial, antioxidant, immunomodulatory, and anti-inflammatory properties, represents a promising therapeutic dressing for the treatment of AD.