Biocompatible and degradable Bletilla striata polysaccharide hemostasis sponges constructed from natural medicinal herb Bletilla striata

Modifications of polysaccharide-based biomaterials under structure-property relationship for biomedical applications

Polysaccharides are well accepted biomaterials that have attracted considerable attention. Compared with other materials under research, polysaccharides show unique advantages: they are available in nature and are normally easily acquired, those acquired from nature show favorable immunogenicity, and are biodegradable and bioavailable. The bioactivity and possible applications are based on their chemical structure; however, naturally acquired polysaccharides sometimes have unwanted flaws that limit further applications. For this reason, carefully summarizing the possible modifications of polysaccharides to improve them is crucial. Structural modifications can not only provide polysaccharides with additional functional groups but also change their physicochemical properties. This review based on the structure-property relation summarizes the common chemical modifications of polysaccharides, the related bioactivity changes, possible functionalization methods, and major possible biomedical applications based on modified polysaccharides.

Improved hemostatic effects by Fe3+ modified biomimetic PLLA cotton-like mat via sodium alginate grafted with dopamine

The development of an excellent, bioabsorbable hemostatic material for deep wound remains a challenge. In this work, a biodegradable cotton-like biomimetic fibrous mat of poly (l-lactic acid) (PLLA) was made by melt spinning. Subsequently, SD composite was prepared by cross-linking sodium alginate (SA) with dopamine (DA). It was immobilized on the fibre surface, which inspired by mussel byssus. Finally, Fe3+ was loaded onto the 0.5SD/PLLA composite by chelation with the carboxyl of alginate and phenolic hydroxy of dopamine. The haemostasis experiment found that the hemostatic time 47 s in vitro. However, the bleeding volume was 0.097 g and hemostatic time was 23 s when 20Fe3+-0.5SD/PLLA was applied in the haemostasis of the rat liver. As a result of its robust hydrophilicity and bouffant cotton-like structure, it could absorb a large water from blood, which could concentrate the component of blood and reduce the clotting time. Furthermore, the addition of Fe3+ in the 0.5SD/PLLA had a significant effect on improve hemostatic property. It also displayed excellent antibacterial property for Escherichia coli and Staphylococcus aureus. Notably, it possesses superior hemocompatibility, cytocompatibility and histocompatibility. Hence, 20Fe3+-0.5SD/PLLA has high potential application in haemostasis for clinical settings due to its outstanding properties.

Investigation into the physical properties, antioxidant and antibacterial activity of Bletilla striata polysaccharide/chitosan membranes

Traditional wound dressings and formulations, such as cream, gauze, cotton wool and gel, are disadvantaged by short residence time, poor leakage and air permeability, poor patient compliance, and the minimal preservation in wet environment. This study is purposed to develop new biodegradable, antioxidant, and antimicrobial membranes based on two natural polysaccharides, Bletilla striata polysaccharide (BSP) and chitosan (CS). The developed films were characterized by SEM, FTIR spectroscopy, NMR spectroscopy and X-ray diffraction to examine surface morphology and internal structure, while TG analysis was conducted to explore the thermal properties of the films. The physical properties of the films were also improved significantly after the introduction of BSP. The biological activity of developed films was assessed by means of antioxidant and antibacterial assay for the further research as a potential wound dressing. The CCK-8 assay revealed that the developed films showed a significant improvement of cell viability, biocompatibility and non-toxicity. These researches demonstrated that BSP/CS films can be applied as suitable materials for the development of biomaterial matrix in novel wound dressing.

Batch preparation of electrospun polycaprolactone/chitosan/aloe vera blended nanofiber membranes for novel wound dressing

At present, more and more attention has been paid to the development of active wound dressings. Chitosan, a kind of carbohydrate polymer with good biocompatibility, is widely used in the field of wound dressings. In this study, a slopeing free surface electrospinning (SFSE) device was presented to prepare large quantities of polycaprolactone/chitosan/aloe vera (PCL/CS/AV) nanofiber membranes (NFMs) for antibacterial wound dressing. And the morphologies of PCL/CS/AV NFMs with varying weight ratios of PCL:CS:AV were studied using SEM, and the optimal weight ratio of 5:3:2 was determined for better wound dressings. Then the structure, wetting property and yield of the PCL/CS/AV NFMs with the optimal weight ratio were investigated, and the effects of the addition of AV on the antibacterial performance and the biocompatibility of NFMs was studied. In addition, the preparation mechanism of SFSE was researched by simulating the electric field distribution using Maxwell 3D due to the important role of the electric field in the SFSE process. The simulation analyses of electric fields agreed with the experimental data. The results illustrated SFSE could prepare high quality PCL/CS/AV NFMs in batches, and its yield of PCL/CS/AV NFMs was 10 times more than the single-needle ES, and the fabricated NFMs showed excellent antibacterial performance and biocompatibility, which made them suitable for wound dressings.

Application of Traditional Chinese Medicines in Postoperative Abdominal Adhesion

Adhesion is a frequent complication after abdominal surgery. Although various methods have been applied to prevent and treat postoperative abdominal adhesion (PAA), few modern drugs designed for clinical applications have reached the expected preventive or therapeutic effect so far. There is an imperative to develop some new strategies for the treatment of PAA. Traditional Chinese medicine (TCM) has been widely practiced for thousands of years and played an indispensable role in the prevention and treatment of diseases. Modern medicine researchers have accepted the therapeutic effects of many active components derived from Chinese medicinal herbs. The review stresses the most commonly used TCM treatment, including Chinese medicinal herbals and monomers, TCM formulas, and acupuncture treatment.