Homogeneous acylation of xylan with 3,5-dinitrobenzoyl in ionic liquid and the adsorption property

Hemicellulose from Plant Biomass in Medical and Pharmaceutical Application: A Critical Review

BACKGROUND

Due to the non-toxicity, abundance and biodegradability, recently more and more attention has been focused on the exploration of hemicellulose as the potential substrate for the production of liquid fuels and other value-added chemicals and materials in different fields. This review aims to summarize the current knowledge on the promising application of nature hemicellulose and its derivative products including its degradation products, its new derivatives and hemicellulosebased medical biodegradable materials in the medical and pharmaceutical field, especially for inmmune regulation, bacteria inhibition, drug release, anti-caries, scaffold materials and anti-tumor.

METHODS

We searched the related papers about the medical and pharmaceutical application of hemicellulose and its derivative products, and summarized their preparation methods, properties and use effects.

RESULTS

Two hundred and twenty-seven papers were included in this review. Forty-seven papers introduced the extraction and application in immune regulation of nature hemicellulose, such as xylan, mannan, xyloglucan (XG) and β-glucan. Seventy-seven papers mentioned the preparation and application of degradation products of hemicellulose for adjusting intestinal function, maintaining blood glucose levels, enhancing the immunity and alleviating human fatigue fields such as xylooligosaccharides, xylitol, xylose, arabinose, etc. The preparation of hemicellulose derivatives were described in thirty-two papers such as hemicellulose esters, hemicellulose ethers and their effects on anticoagulants, adsorption of creatinine, the addition of immune cells and the inhibition of harmful bacteria. Finally, the preparations of hemicellulose-based materials such as hydrogels and membrane for the field of drug release, cell immobilization, cancer therapy and wound dressings were presented using fifty-five papers.

CONCLUSION

The structure of hemicellulose-based products has the significant impact on properties and the use effect for the immunity, and treating various diseases of human. However, some efforts should be made to explore and improve the properties of hemicellulose-based products and design the new materials to broaden hemicellulose applications.

Stability of BiFeO3 nanoparticles via microwave-assisted hydrothermal synthesis in Fenton-like process

Stable catalysts require high catalytic efficiency and repeated consecutive use, low mass loss, and metal leaching. This study investigated BiFeO₃ (BFO) composite with high stability and reusability using a one step microwave-assisted hydrothermal method (MAHS) to decompose bisphenol A (BPA) used as the target contaminant. After six consecutive reaction cycles in microwave-enhanced Fenton-like process (MW-Fenton-like), the removal rate of BPA decreased from 94 to 87.4% with low metal leaching ratio and mass loss. The morphology, crystal, reaction kinetics, and hydroxyl radical (·OH) were used to demonstrate the high stability of BFO-MAHS. The results indicated that the benign stability and reusability of BFO-MAHS probably occurred because (1) the thermal-effect of MW improved heating rate, which led to the rapid formation stable cube structure and (2) MW mechanical vibrations existed in the preparation process, which further enhanced the cube structure. Therefore, MAHS could be used as a green and environmental friendly method to apply in catalysts synthesis, which could immensely shorten preparation time and enhance the catalytic performance with no waste production.

Synthesis of Acylated Xylan-Based Magnetic Fe₃O₄ Hydrogels and Their Application for H₂O₂ Detection

Acylated xylan-based magnetic Fe₃O₄ nanocomposite hydrogels (ACX-MNP-gels) were prepared by fabricating Fe₃O₄ nanoctahedra in situ within a hydrogel matrix which was synthesized by the copolymerization of acylated xylan (ACX) with acrylamide and N-isopropylacrylamide under ultraviolet irradiation. The size of the Fe₃O₄ fabricated within the hydrogel matrix could be adjusted through controlling the crosslinking concentrations (C). The magnetic hydrogels showed desirable magnetic and mechanical properties, which were confirmed by XRD, Raman spectroscopy, physical property measurement system, SEM, TGA, and compression test. Moreover, the catalytic performance of the magnetic hydrogels was explored. The magnetic hydrogels (C = 7.5 wt %) presented excellent catalytic activity and provided a sensitive response to H₂O₂ detection even at a concentration level of 5 × 10^-6 mol·L^-1. This approach to preparing magnetic hydrogels loaded with Fe₃O₄ nanoparticles endows xylan-based hydrogels with new promising applications in biotechnology and environmental chemistry.