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 natural microneedles based methacrylated Bletilla striata polysaccharide for repairing chronic wounds with bacterial infections.

The expeditious healing of chronic wounds with bacterial infections poses a formidable challenge in clinical practice because of the persistent bacterial presence, excessive inflammation, and the accumulation of reactive oxygen species (ROS) in clinical practice. Thus, in this study, natural antimicrobial material microneedles (MNs) with multifunctional properties were prepared by adding peony leaf extract (PLE) into a matrix of methacrylated Bletilla striata polysaccharide (BSPMA) and methacrylated chitosan (CSMA) via cross-linking under ultra-violet light to accelerate the rapid healing of chronic wounds with bacterial infections. Results showed that BCP-MNs effectively inhibited the growth of Escherichia coli, Staphylococcus aureus, and methicillin-resistant S. aureus (MRSA) by disrupting bacterial cell membranes and accelerated the healing of infected wounds by enhancing cell migration, epidermal regeneration, pro-collagen deposition, and angiogenesis and reducing inflammation. Furthermore, BCP-MNs not only possessed good mechanical properties, stability, and biocompatibility but also showed potent antioxidant effects to eliminate excessive ROS accumulation in the wound bed. In conclusion, BCP-MNs possess multifunctional wound-healing properties and can serve as excellent wound dressing in to treat infected wounds.

Development of the mussel-inspired pH-responsive hydrogel based on Bletilla striata polysaccharide with enhanced adhesiveness and antioxidant properties.

Recently, smart hydrogels have attracted much attention for their abilities to respond to subtle changes in external and internal stimuli. Also, natural polysaccharide-based biomaterials are more appealing for their biocompatibility and biodegradability. However, limitations owing to their complex compositions and mechanisms, cumbersome synthetic routes, and single function call for a simple and effective strategy to develop novel multifunctional smart hydrogels. Herein, this developed work was achieved based on Bletilla striata polysaccharide (BSP), a kind of natural glucomannan with diverse bioactivities and biocompatibility, we fabricated a low-cost multifunctional hydrogel by oxidizing the catechol groups of carboxymethylated BSP(CBSP)-dopamine(DA) conjugate with adhesion, antioxidant, and pH-responsive properties. In this hydrogel system, CBSP as the backbone material, was negatively charged and conferred the hydrogel with pH sensitivity. The presence of catechol groups greatly enhanced the tissue adhesion and antioxidant capacities of the hydrogel. Meanwhile, the highly porous structure of hydrogel allowed berberine to be encapsulated and released to exhibit excellent and long-lasting antibacterial activity. In summary, the adhesion, antioxidant, pH-sensitive, and antibacterial multifunctional hydrogel showed massive potential in the biomedical field.