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.

Preparation of chitosan/peony (Paeonia suffruticosa Andr.) leaf extract composite film and its application in sustainable active food packaging.

Considering the problem of food perishability and the environmental pollution of plastic packaging, the natural active packaging prepared by incorporating plant leaf (e.g. peony leaf) extract into biodegradable food packaging materials may be a key to addressing these issues. In the study, a novel green bioactive composite film (CS-PLE) with antioxidant and antibacterial propertiese was developed by blending peony leaf extract (PLE) into chitosan (CS) film through the solution casting method. The physical properties and biological activities of a series of films, including CS film and CS-PLEs incorporated with different concentrations of PLE, were studied by appropriate experimental protocols. The results demonstrated that addition of PLE improved thermal stability, the barrier performance of UV-A and total phenolic content of CS film, and the antioxidant activities of CS-PLEs increased by 60.6 % ~ 73.2 % with the appending proportion of PLE from 0.1 wt% ~ 0.7 wt% compared to CS film. Furthermore, CS-PLEs had better inhibiting effect on bacteria. Notably, CS-PLE (0.7 wt%) wrapping apples showed the least degree of browning among all the groups. Hence, the study of CS-PLEs can provide a new strategy for the preparation of food packaging materials that are green alternatives and reduce environmental pollution.

In-situ synthesis silver nanoparticles in chitosan/Bletilla striata polysaccharide composited microneedles for infected and susceptible wound healing.

A novel antibacterial strategy is urgently required to develop for solving bacterial biofilm obstruction and bacterial drug resistance in the infected wound healing process. Herein, the Chitosan/Bletilla striata polysaccharide composited microneedles were prepared by chitosan, tannic acid, AgNO3 and Bletilla striata polysaccharide through step centrifugation. In our design system, the porous structure of microneedles gradually disappeared, and the mechanical properties were significantly improved after multiple fillings. Ag+ is reduced in-situ to silver nanoparticles by the abundant polyphenols of tannic acid, displaying antibacterial effects both in vitro and vivo, even for methicillin resistant Staphylococcus aureus. The addition of Bletilla striata polysaccharide increased the ability of piercing biofilm and promoted wound healing. The microneedles exhibited good biocompatibility and with function of piercing the bacterial biofilms, scavenging excessive free radicals, inhibiting inflammatory factors, and promoting wound healing. Therefore, the multifunctional composited microneedles show great potential to promote infected and susceptible wound healing.

[Progress in application of Bletilla striata polysaccharide in novel drug delivery systems and biomaterials].

As the main active ingredient of the orchidaceous herb Bletilla striata, B. striata polysaccharide(BSP) has pharmacological activities such as promoting coagulation, anti-inflammation, anti-oxidation, promoting wound healing, anti-tumor, and immunomodulation, and is biodegradable and non-toxic. Additionally, it has the material properties of suspension thickening, film-forming adhesion, coating and solubilizing, targeting and slow releasing, effect-enhancing and toxicity-reducing, etc., playing the role of unification of medicines and excipients. Therefore, BSP has a wide application prospect in the fields of drug delivery system and trauma repair. This paper reviews the research progress of BSP application in new drug delivery systems and biomaterials based on the related li-terature in recent years, with the aim of providing reference for the further research and application of BSP.

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.