Synthesis of a reduction-sensitive Bletilla striata polysaccharide amphiphilic copolymer

Effects of Different Drying Methods on the Quality of Bletilla striata Scented Tea

Flower tea is widely loved as a drink, especially for the beautiful and rich flowers of the orchid family, and the drying method for different flowers is also unique. GC-MS is widely used to study volatile substances to determine the quality of flower teas. The findings show that the freeze-drying method can retain the original aroma and flavor of Bletilla striata has the highest sensory evaluation score, with the key flavor substances ethyl caproate and N-heptanal containing 1.14% and 6.28%, respectively, and their ROAV values reaching 54.46 and 100.00. Additionally, the freeze-drying method can well retain flavonoids, polysaccharides, and phenolic components, while providing better antioxidant and antibacterial properties. The stove-drying method would make Bletilla striata slightly burnt and less flavorful and efficacious than freeze-drying; the air-drying method is difficult to retain the special odor and fragrance of Bletilla striata flowers and has the lowest sensory evaluation score, with the presence of volatile components with irritating and unpleasant odors such as pyrazine and 2-pentylfuran, while not showing better efficacy. In addition, steam fixation would destroy the morphology and flavor of Bletilla striata, lose polysaccharide and phenolic components, and reduce the efficacy of Bletilla striata scented tea, but could retain the flavonoid components well. In summary, direct freeze-drying without steam fixation is the best process for drying Bletilla striata scented tea, stove-drying without steam fixation is more economical and convenient in actual production and application, steam fixation and air-drying are not suitable as drying processes for Bletilla striata scented tea. This study analyzed the quality of Bletilla striata scented tea under different drying methods, promoted the further processing of Bletilla striata scented tea, and provided a reference for the comprehensive utilization of Bletilla striata scented tea.

Polysaccharide hydrogels: Functionalization, construction and served as scaffold for tissue engineering

Polysaccharide hydrogels have been widely utilized in tissue engineering. They interact with the organismal environments, modulating the cargos release and realizing of long-term survival and activations of living cells. In this review, the potential strategies for modification of polysaccharides were introduced firstly. It is not only used to functionalize the polysaccharides for the consequent formation of hydrogels, but also used to introduce versatile side groups for the regulation of cell behavior. Then, techniques and underlying mechanisms in inducing the formation of hydrogels by polysaccharides or their derivatives are briefly summarized. Finally, the applications of polysaccharide hydrogels in vivo, mainly focus on the performance for alleviation of foreign-body response (FBR) and as cell scaffolds for tissue regeneration, are exemplified. In addition, the perspectives and challenges for further research are addressed. It aims to provide a comprehensive framework about the potentials and challenges that the polysaccharide hydrogels confronting in tissue engineering.

Bio-responsive Bletilla striata polysaccharide-based micelles for enhancing intracellular docetaxel delivery

The aim of this study was to design a pH- and redox-dual responsive Bletilla striata polysaccharide (BSP)-based copolymer to enhance anti-tumor drugs release at tumor sites and improve the therapeutic effect. The copolymer was synthesized using stearic acid (SA) and cystamine via a disulfide linkage and characterized using 1H-Nuclear Magnetic Resonance spectroscopy and Fourier Transform Infrared spectroscopy. The BSP-ss-SA copolymer could self-assemble into micelle in an aqueous environment and could encapsulate docetaxel therein. Its inhibitory effects on HepG2 cells and 4 T1 cells were determined. Besides, the anti-cancer effects in vivo and histopathological study of 4 T1-bearing tumor mice were also evaluated. Docetaxel-loaded BSP-ss-SA micelles showed significant pH-sensitive release behavior, supplying a greater drug release percentage in pH 5.0 media compared to pH 7.4 media. BSP-ss-SA micelles exhibited a clear redox-responsive release property in pH 7.4 media whereas the similar cumulative release percentage of docetaxel from BSP-ss-SA micelles in pH 5.0 media in the presence and absence of DL-dithiothreitol. The Docetaxel-loaded BSP-ss-SA micelles clearly inhibited the proliferation of HepG2 and 4 T1 cells compared with docetaxel solution. The results of MTT and histopathological study indicated that BSP-ss-SA copolymer exhibited good blood compatibility. The BSP-ss-SA copolymer may be used as carriers to deliver anti-tumor drugs to special tumor tissues.