Polyphenol-Based Nanosystems for Next-Generation Cancer Therapy: Multifunctionality,Design, and Challenges

With the continuous updating of cancer treatment methods and the rapid development of precision medicine in recent years, there are higher demands for advanced and versatile drug delivery systems. Scientists are committed to create greener and more effective nanomedicines where the carrier is no longer limited to a single function of drug delivery. Polyphenols, which can act as both active ingredients and fundamental building blocks, are being explored as potential multifunctional carriers that are efficient and safe for design purposes. Due to their intrinsic anticancer activity, phenolic compounds have shown surprising expressiveness in ablation of tumor cells, overcoming cancer multidrug resistance (MDR), and enhancing immunotherapeutic efficacy. This review provides an overview of recent advances in the design, synthesis, and application of versatile polyphenol-based nanosystems for cancer therapy in various modes. Moreover, the merits of polyphenols and the challenges for their clinical translation are also discussed, and it is pointed out that the novel polyphenol delivery system requires further optimization and validation.     

金属有机框架(MOFs)材料在锂离子电池及锂金属电池电解液中的应用

总结了金属有机框架(MOFs)材料在锂离子电池电解液中的研究进展.通过归纳锂离子电池长期存在的一些缺陷,随后将MOFs材料作为离子筛、人造负极保护层、准固态电解质以及用来调节电解液构型,使得锂离子电池的性能得到显著提升.最后,基于MOFs材料本身的特性,还对MOFs材料在电化学储能领域中的后续应用进行了合理地前瞻性展望...     

Strategies for the construction of supramolecular assemblies from poly-NHC ligand precursors

The field of supramolecular assemblies has developed rapidly in the last few decades, thanks in a large part to their diverse applications. These assemblies have been mostly based on Werner-type coordination motifs in which metal centres are coordinated by nitrogen or oxygen donors. Recently, N-heterocyclic carbene(NHC) ligands have been employed as carbon donors not only because of their appealing structures but also due to the extensive applications in catalysis, biomedicine and material science of the resulting assemblies. During the last decade, NHC-based supramolecular assemblies have witnessed rapid growth and extensive application in molecular recognition, luminescent materials and catalysis. For different topological systems, a diverse selection of poly-NHC precursors and synthetic strategies is crucial to precisely control the synthesis of supramolecular architectures. Several synthetic strategies have been developed to synthesise two-dimensional(2D) molecular metallacycles and three-dimensional(3D) metallacages from a wide range of poly-NHC precursors, including a straightforward one-pot strategy,supramolecular transmetalation, stepwise synthesis, an improved one-pot strategy involving self-sorting behaviour of 3D metallacages and a subtle variation strategy of poly-NHC ligand precursors. This review offers a summary of the synthetic strategies applied for the construction of different poly-NHC-based supramolecular assemblies, particularly emphasizes recent progress in the synthesis of large and complex supramolecular assemblies from poly-NHC precursors, and further attention is given to their application in postsynthetic modifications(PSMs), host-guest chemistry, luminescent properties and biomedical applications.     

锆氢催化的酰胺硼氢化合成胺类化合物研究:机理、使用范围和应用

发展温和条件下胺类化合物的高效合成方法是催化与合成领域长期研究的课题.其中,酰胺还原因其原料来源广、易于合成而广受关注.酰胺还原到胺需要选择性断裂C=O键,因此该反应具有很大的挑战性.传统酰胺还原方法需要使用当量的强还原试剂,如四氢铝锂、硼氢化钠等,且官能团兼容性较差.使用氢气还原原子经济性最高,也最有吸引力;然而,目前已报道的体系大都在高温(>120℃)或高压(>40 bar H2)的条件下进行.虽然催化硼氢化可以在温和的条件下将羰基化合物还原,但由于酰胺化合物惰性比较高,其选择性的催化硼氢化研究则相对较少,而且在温和条件下对三级、二级、一级酰胺都适用的例子依然非常有限.本文采用前过渡金属锆氢催化剂实现了室温条件下酰胺选择性硼氢化制备胺类化合物,并进行了详细的机理研究.原位红外监测到反应过程中酰胺和硼烷逐渐减少,目标产物逐渐增多;但并未给出其他反应中间体的信息.核磁研究以及对照实验结果表明,反应中有苯甲醛的生成,可能是反应中间体.因此推测,该催化体系经历了锆氢介导的酰胺C?N键断裂、重组、C?O键断裂这一特殊的酰胺键活化转化过程.DFT计算也证实了上述反应历程的可行性.除一些常见官能团外,本方法对羧酸酯、氰基、硝基、烯烃和炔烃这些可能被硼氢化的官能团同样具有兼容性.而且本文体系对一些生物、药物分子衍生酰胺的硼氢化也可以顺利进行.可见,本文发展了一种温和条件下使用廉价催化剂和原料选择性合成胺类化合物的方法.     

改性钛基PbO2电极的制备及其对COD的快速检测

通过制备Ti/α/β-PbO₂、Ti/Ag/β-PbO₂这两种含有不同中间层的钛基二氧化铅电极来探究电催化氧化技术快速测定葡萄糖模拟废水中有机物(COD)含量的可行性。为了评估两种电极的各项性能,首先采用扫描电镜(SEM)、X射线衍射(XRD)对电极进行形貌表征,其次进行电化学性能测试包括线性伏安曲线(LSV)、塔菲尔曲线(Tafel)、循环伏安曲线(CV)以及交流阻抗测量分析。结果表明,Ti/α/β-PbO₂电极表面晶体结构更加均匀,晶粒尺寸偏小,具有更大的电活性表面积。Ti/α/β-PbO₂电极的析氧电位为1.77 V,为·OH的产生提供良好条件。在Tafel、CV测试中,Ti/α/β-PbO₂电极的交换电流密度i₀及比电容C_p分别为0.0995 A·cm^-1、0.004098 F·cm^-1均高于Ti/Ag/β-PbO₂电极,说明Ti/α/β-PbO₂电极的耐腐蚀性以及释放电子的能力优异。最终选用Ti/α/β-PbO₂电极为工作电极。Ti/α/β-PbO₂电极检测COD的最佳条件为：氧化电位1.30 V、电解时间150 s、电解液浓度0.03 mol·L^-1 硝酸钠(NaNO₃)。电化学法与比色消解法测定COD的相关系数可达0.9909,同时具有良好的重现性与相关性,COD的检测范围为0 mg·L^-1 ~ 500 mg·L^-1。在误差允许的范围内可以替代标准的重铬酸钾法,为实现COD的在线快速检测提供参考价值。     

Synthesis and Structure–Activity Relationship Studies of Benzimidazole-4,7-dione-Based P2X3 Receptor Antagonists as Novel Anti-Nociceptive Agents

P2X3 receptors (P2X3R) are ATP-gated ion channels predominantly expressed in C- and Aδ-fiber primary afferent neurons and have been introduced as a novel therapeutic target for neurological disorders, including neuropathic pain and chronic cough. Because of its localized distribution, antagonism of P2X3R has been thoroughly considered, and the avoidance of issues related to CNS side effects has been proven in clinical trials. In this article, benzimidazole-4,7-dione-based derivatives were introduced as a new chemical entity for the development of P2X3R antagonists. Starting from the discovery of a hit compound from the screening of 8364 random library compounds in the Korea Chemical Bank, which had an IC₅₀ value of 1030 nM, studies of structure–activity and structure–property relationships enabled further optimization toward improving the antagonistic activities as well as the drug’s physicochemical properties, including metabolic stability. As for the results, the final optimized compound 14h was developed with an IC₅₀ value of 375 nM at P2X3R with more than 23-fold selectivity versus P2X2/3R, along with properties of metabolic stability and improved solubility. In neuropathic pain animal models evoked by either nerve ligation or chemotherapeutics in male Sprague-Dawley rats, compound 14h showed anti-nociceptive effects through an increase in the mechanical withdrawal threshold as measured by von Frey filament following intravenous administration.     

Optimization of Naringenin Nanoparticles to Improve the Antitussive Effects on Post-Infectious Cough

Naringenin (NRG) is a natural compound with several biological activities; however, its bioavailability is limited owing to poor aqueous solubility. In this study, NRG nanoparticles (NPs) were prepared using the wet media milling method. To obtain NRG NPs with a small particle size and high drug-loading content, the preparation conditions, including stirring time, temperature, stirring speed, and milling media amount, were optimized. The NRG (30 mg) and D-α-tocopherol polyethylene glycol succinate (10 mg) were wet-milled in deionized water (2 mL) with 10 g of zirconia beads via stirring at 50 °C for 2 h at a stirring speed of 300 rpm. As a result, the NRG NPs, with sheet-like morphology and a diameter of approximately 182.2 nm, were successfully prepared. The NRG NPs were stable in the gastrointestinal system and were released effectively after entering the blood circulation. In vivo experiments indicated that the NRG NPs have good antitussive effects. The cough inhibition rate after the administration of the NRG NPs was 66.7%, cough frequency was three times lower, and the potential period was 1.8 times longer than that in the blank model group. In addition, the enzyme biomarkers and histological analysis results revealed that the NRG NPs can effectively regulate the inflammatory and oxidative stress response. In conclusion, the NRG NPs exhibited good oral bioavailability and promoted antitussive and anti-inflammatory effects.     

Comparison of the Antioxidant Activities and Polysaccharide Characterization of Fresh and Dry Dendrobium officinale Kimura et Migo

It is generally believed that fresh Dendrobium officinale (FDO) has more significant pharmacological activity than dried Dendrobium officinale (DDO); however, the difference has not been clearly shown. Our study compared their antioxidant properties both in vitro and in vivo, and the molecular weight arrangement and monosaccharide composition of the fresh Dendrobium officinale polysaccharides (FDOPs) and the dried Dendrobium officinale polysaccharides (DDOPs) were analyzed by HPLC-GPC and GC-MS. The results showed that the FDO and its polysaccharides had more significant effects on scavenging DPPH, ABTS, and hydroxyl radicals than the DDO. In addition, both the FDO and DDO significantly reduced lipid peroxidation levels and increased the SOD, T-AOC, CAT, and GSH levels in mice with acute liver damage caused by CCl₄, while the FDO and its polysaccharides were more effective. Histopathological analysis further verified the protective effect of the Dendrobium polysaccharides on CCl₄-induced liver injury. The determination of the polysaccharides revealed that the polysaccharide and mannose contents of the FDO were significantly higher than their dried counterparts, and the homogeneous arrangement of the polysaccharides in the FDO was degraded into three polysaccharide fragments of different molecular weights in the DDO. Overall, our data identified differences in the antioxidant activities of the FDO and DDO, as well as the reasons for these differences.     

密度泛函理论下的分子总体电负性与调和平均电负性的关系

根据密度泛函理论定义的有效原子电负性，讨论了分子中总体电负性与调和平均电负性之间的关系，得到了调和平均电负性非常接近于总体电负性的结论，同时，说明了两者相似的原因，并对一系列分子给出了它们的数值比较．     

Determination of trace elements in human serum by inductively coupled plasma atomic emission spectrometry with flow injection

An analytical method for the simultaneous determination of some trace elements (Au, Fe, Mg, Li, Sr, Zn) in human serum by inductively coupled plasma atomic emission spectrometry (ICP-AES) with flow injection is described. Physical interference caused by the change of sample viscosity is discussed. When 100 μl of serum was injected, the relevant recoveries of > 99% for Li, > 98% for Cu and Mg, > 95% for Fe were obtained for an NIST SRM with R.S.D. > 1.3% using optimized flow injection parameters. The prepared lyophilized control serum for routine analysis in clinical laboratories was analyzed and verified for the validity of the technique employed in this experiment using NIST SRM 909 as a primary reference material.