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BACKGROUND: A polysaccharide was purified in this study, which was acquired from the fermentation broth of Dendrobium officinale Kimura et Migo. We aimed to investigate the structural features and bioactivity of this polysaccharide. RESULTS: The polysaccharide was purified and the main polysaccharide fraction (i.e., DOP‐1) was obtained. High‐performance gel permeation chromatography (HPGPC) revealed that the molecular weight of DOP‐1 was 447.48 kDa. Galactose, glucose and mannose were found to be present in DOP‐1 via monosaccharide composition analysis, at a ratio of 1:1.79:6.71. Methylation and nuclear magnetic resonance spectroscopic analysis indicated that the backbone of DOP‐1 was →4)‐α‐d‐Glcp‐(1 → 4)‐α‐d‐Manp‐(1 → 4)‐α‐d‐Manp‐(1 → 4,6)‐α‐d‐Manp‐(1→, and its repeating units were also preliminarily established. In vitro tests proved that DOP‐1 not only protects RAW264.7 macrophages from the cytotoxic effect induced by lipopolysaccharide (LPS), but also inhibits cytokines (i.e., interleukin‐6 and tumour necrosis factor‐α) induced by LPS. DOP‐1 demonstrated good scavenging activity in vitro toward 1,1‐diphenyl‐2‐picrylhydrazyl and hydroxyl radicals, as well as good metal chelating activity. Therefore, DOP‐1 has potential antioxidant applications. CONCLUSION: The structural characteristics of DOP‐1 support its favourable biological activities and lay a strong foundation for further exploration of its structure–activity relationships and activity development, providing experimental data for the development and utilisation of fermentation broth of D. officinale. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A novel thermoelectricity composite material that n-type pseudo-ternary (Bi2Te3)0.90(Sb2Te3)0.05(Sb2Se3)0.05 alloy doped with Er is prepared by mechanical alloying under 177 MPa pressure. The effects of process parameters on the microstructure of the composite are studied. The impact mechanism of the erbium doping concentration and hot-pressing temperature on the Seebeck coefficient and electrical conductivity of the material is discussed in detail. The best erbium doping concentration of the prepared composite is obtained as 0.5 wt%. The basic law of the Seebeck coefficient and the electrical conductivity with the pressing temperature is established. The material microstructure and carrier concentration affected by process parameters are the main reason leading changes of the thermoelectric properties. [ABSTRACT FROM AUTHOR]

A correction to the article "Different Inhibitory Effect and Mechanism of Hydroxyapatite Nanoparticles on Normal Cells and Cancer Cells In Vitro and In Vivo" that was published in the previous issue, is presented.

Controlling the crystal size and surface chemistry of MOF materials, and understanding their multifunctional effect are of great significance for the biomedical applications of MOF systems. Herein, we designed and synthesized a new anionic MOF, ZJU-64-NSN, which features 1D channels decorated with highly polarized thiadiazole groups, and its crystal size could be systematically tuned from 200 ​μm to 300 ​nm through a green and simple approach. As a result, the optimal nanosized ZJU-64-NSN is found to enable an ultrafast loading of cationic drug procainamide (PA) (21.2 ​wt% within 1 ​min). Moreover, the undesirable chemical stability of PA@ZJU-64-NSN is greatly improved by the surface coating of polyethylene glycol (PEG) biopolymer. The final drug delivery system PEG/PA@ZJU-64-NSN is found to effectively prevent PA from premature release under the harsh stomach environments due to the intense host-guest interaction, and mainly release PA to the targeted intestinal surroundings. Such controlled drug delivery is proved to be triggered by endogenic Na + ions instead of H + ions, well revealed by the study on the dynamics behavior of drug release and UV-Vis absorption spectrum. Good biocompatibility of ZJU-64-NSN and PEG-coated ZJU-64-NSN has been fully demonstrated by MTT assay as well as confocal microscopy imaging., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 Published by Elsevier Ltd.)

This study aims to investigate the effects of small interference RNA (siRNA) targeting PML-RARa mRNA on the activity of the acute promyelocytic leukemia cell line NB4. The proliferation inhibition was evaluated by MTT assay and colony-formation inhibiting test. Apoptosis was determined by flow cytometry after siRNA treatment. The results showed that the cell growth of siRNA treated group was inhibited, and the apoptosis of NB4 could be induced. The siRNA targeting PML-RARα mRNA might be a valid therapy of acute promyelocytic leukemia.

To evaluate the sealing potential of self-designed root canal filling material made of calcium phosphate cement (alpha-TCP/TTCP, CPC), the apices of root canals of six adult dogs were purposely perforated and enlarged up to the No 40 instrument. Then CPC was used to fill the root canal. Mean while either calcium hydroxide (Ca(OH)2) paste or hydroxyapatite (HA) paste was used as control. The animals were killed at 4, 12, 20 weeks postoperatively. The different materials about ways of apical closure, restoration periapocal tissues and adaptability to the dentinal surface were observed by histomorphology and scanning electron microscopic. This study revealed that CPC had excellent biocompatibility and adaptability to the dentinal wall. Its osteoconduction can promote the formation of calcific barriers and healing of periapical tissue. The apex can be closed completely. Compared with the control pastes it has advantages of ease of manipulation and better sealing capability. The results showed that CPC could be used as a root canal filling material for pupless teeth with open apex and destructive periapical tissue.

A biological evaluation is conducted for two types of nano-particle sols, hydroxyaptite(HAP) and titanium dioxide(TiO2). The results show that HAP sol significnatly prolongs the bleeding time and coagulation time of mice as well as the prothrombin time(PT) and partial thromboplastin time(PTT) of rats while TiO2 sol exhibits no such effects. Neither HAP sol nor TiO2 sol instigated in-vitro hemolysis of rabbit erythrocyte. However, both of the materials caused in-vitro aggregation of rabbit erythrocytes. The reason underlying the different results as to the two types of material is their specific stabilizer, heparin for HAP sol and PVC for TiO2 sol. We came to the conclusion that a biologically inert stablizer has no less significance than the nano-particle's very own nature in a nano-material's application prospect.