Injectable Antiswelling and High-Strength Bioactive Hydrogels with a Wet Adhesion and Rapid Gelling Process to Promote Sutureless Wound Closure and Scar-free Repair of Infectious Wounds

Developing injectable antiswelling and high-strength bioactive hydrogels with wet tissue adhesiveness and a rapid gelling process to meet the requirements for rapid hemostasis, sutureless wound closure, and scar-free repair of infected skin wounds continues to have ongoing challenges. Herein, injectable, antibacterial, and antioxidant hydrogel adhesives based on poly(citric acid-co-polyethylene glycol)-g-dopamine and amino-terminated Pluronic F127 (APF) micelles loaded with astragaloside IV (AS) are prepared. The H2O2/horseradish peroxidase (HRP) system is used to cause cross-linking of the hydrogel network through oxidative coupling between catechol groups and chemical cross-linking between the catechol group and the amino group. The hydrogels exhibit a rapid gelling process, high mechanical strength, an antiswelling effect, good antioxidant property, H2O2 release behavior, and degradability. In addition, the hydrogels present good wet tissue adhesiveness, high bursting pressure, excellent antibacterial activity, long-term sustained release of AS, and good biocompatibility. The hydrogels perform good hemostasis on mouse liver, rat liver, and rabbit femoral vein bleeding models and achieve much better closure and healing of skin incisions than biomedical glue and surgical sutures. Furthermore, the hydrogel dressing significantly improved the scar-free repair of MRSA-infected full thickness skin defect wounds by modulating inflammation, regulating the ratio of collagen I/III, and improving the vascularization and granulation tissue formation. Thus, AS-loaded hydrogels show huge potential as multifunctional dressings for in vivo hemostasis, sutureless wound closure, and scar-free repair of infected skin wounds.