A sesbania gum/γ-polyglutamic acid photo-crosslinking composite hydrogel loaded with multi-component traditional Chinese medicine extract synergize microenvironment amelioration in infected diabetic wound healing

The intricate physiological microenvironment of the diabetic wound characterized by overexpressed reactive oxygen species (ROS), persistent inflammation, angiogenetic dysfunction, and bacterial infection impeded the healing process. Herein, a photo-crosslinking composite hydrogel was fabricated based on the methacrylate modification of sesbania gum (SG) and γ-polyglutamic acid (γ-PGA), which could trigger free radical polymerization to form interpenetrating polymer network under 365 nm UV. Meanwhile, the micronized traditional Chinese medicine Huoxue Tongluo extract (HXTL) was encapsulated into the hydrogel to prepare the wound dressing (H-SGPGA). The 1 H NMR and FT-IR successfully confirmed the synthesis of the methacrylate SG (SGMA) and γ-PGA (γ-PGAMA). Then, the enhanced mechanical properties, ROS scavenging (DPPH: 88.2 ± 0.9 %; ABTS+: 90.5 % ± 0.4 %) and the antibacterial capacity (97.04 % ± 0.58 % against S. aureus ) of H-SGPGA was investigated and confirmed in vitro . Finally, in the S. aureus infected diabetic wound model, the in vivo result demonstrated that the H-SGPGA significantly accelerated the diabetic wound repair process (8.31 % ± 5.54 % wound area on day 12) by promoting epidermis regeneration (79.13 % ± 5.99 %), collagen deposition (71.4 % ± 9.1 %), and angiogenesis (294.1 % ± 29.6 % of control group). Therefore, the composite H-SGPGA provided a potential treatment as the hydrogel dressing for the diabetic wound.