A dual network cross-linked hydrogel with multifunctional Bletilla striata polysaccharide/gelatin/tea polyphenol for wound healing promotion

Wound healing is a dynamic and complex biological process, and traditional biological excipients cannot meet the needs of the wound healing process, and there is an urgent need for a biological dressing with multifunctionality and the ability to participate in all stages of wound healing. This study developed tea polyphenol (TP) incorporated multifunctional hydrogel based on oxidized Bletilla striata polysaccharide (OBSP) and adipic acid dihydrazide modified gelatin (Gel-ADH) with antimicrobial, antioxidant hemostatic, and anti-inflammatory properties to promote wound healing. The composite OBSP, Gel-ADH, TP (OBGTP) hydrogels prepared by double crosslinking between OBSP, TP and Gel-ADH via Schiff base bonding and hydrogen bonding had good rheological and swelling properties. The introduction of TP provided the composite hydrogel with excellent antioxidant antibacterial activities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coil). In the rat liver hemorrhage model and skin injury model, the OBGTP composite hydrogel had significant (p < 0.001) hemostatic ability, and had the ability to accelerate collagen deposition, reduce the expression of inflammatory factors, and promote rapid wound healing. In addition, OBGTP hydrogels had adhesive properties and good biocompatibility. In conclusion, OBGTP multifunctional composite hydrogels have great potential for wound healing applications.

Multifunctional Bletilla striata polysaccharide/copper/peony leaf sponge for the full-stage wound healing

Conventional wound dressings fail to satisfy the requirements and needs of wounds in various stages. It is challenging to develop a multifunctional dressing that is hemostatic, antibacterial, anti-inflammatory, and promotes wound healing. Therefore, this study aimed to develop a multifunctional sponge dressing for the full-stage wound healing based on copper and two natural products, Bletilla striata polysaccharide (BSP) and peony leaf extract (PLE). The developed BSP-Cu-PLE sponges were characterized by SEM, XRD, FTIR, and XPS to assess micromorphology and elemental composition. Their properties and bioactivities were also verified by the further experiments, whereby the findings revealed that the BSP-Cu-PLE sponges had improved water absorption and porosity while exhibiting excellent antioxidative, biocompatible, and biodegradable properties. Moreover, the antibacterial test revealed that BSP-Cu-PLE sponges had superior antibacterial activity against S. aureus and E. coli. Furthermore, the hemostatic activity of BSP-Cu-PLE sponges was significantly enhanced in a rat liver trauma model. Most notably, further studies have demonstrated that the BSP-Cu-PLE sponges could significantly (p < 0.05) accelerate the healing process of skin wounds by stimulating collagen deposition, promoting angiogenesis, and decreasing inflammatory cells. In summary, the BSP-Cu-PLE sponges could provide a new strategy for application in clinical setting for full-stage wound healing.