Versatile chondroitin sulfate-based nanoplatform for chemo-photodynamic therapy against triple-negative breast cancer.

Versatile nanoplatform equipped with chemo-photodynamic therapeutic attributes play an important role in improving the effectiveness of tumor treatments. Herein, we developed multifunctional nanoparticles based on chondroitin sulfate A (CSA) for the targeted delivery of chlorin e6 (Ce6) and doxorubicin (DOX), in a combined chemo-photodynamic therapy against triple-negative breast cancer. CSA was chosen for its hydrophilic properties and its affinity to CD44 receptor-overexpressed tumor cells. The CSA-ss-Ce6 (CSSC) conjugate was synthesized utilizing a disulfide linker. Subsequently, DOX-loaded CSSC (CSSC-D) nanoparticles were fabricated, showcasing a nearly spherical shape with an average particle size of 267 nm. In the CSSC-D nanoparticles, the chemically attached Ce6 constituted 1.53 %, while the physically encapsulated DOX accounted for 8.11 %. Both CSSC-D and CSSC nanoparticles demonstrated a reduction-sensitive release of DOX or Ce6 in vitro. Under near-infrared (NIR) laser irradiation, CSSC-D showed the enhanced generation of reactive oxygen species (ROS), improving cytotoxic effects against triple-negative breast cancer 4T1 and MDA-MB-231 cells. Remarkably, the CSSC-D with NIR exhibited the most potent tumor growth inhibition in comparison to other groups in the 4T1-bearing Balb/c mice model. Overall, this CSSC-D nanoplatform shows significant promise as a powerful tool for a synergetic approach in chemo-photodynamic therapy in triple-negative breast cancer.

Innovative gelatin-based micelles with AS1411 aptamer targeting and reduction responsiveness for doxorubicin delivery in tumor therapy.

Herein, we constructed innovative reduction-sensitive and targeted gelatin-based micelles for doxorubicin (DOX) delivery in tumor therapy. AS1411 aptamer-modified gelatin-ss-tocopherol succinate (AGSST) and the control GSST without AS1411 modification were synthesized and characterized. Antitumor drug DOX-containing AGSST (AGSST-D) and GSST-D nanoparticles were prepared, and their shapes were almost spherical. Reduction-responsive characteristics of DOX release in vitro were revealed in AGSST-D and GSST-D. Compared with non-targeted GSST-D, AGSST-D demonstrated better intracellular uptake and stronger cytotoxicity against nucleolin-overexpressed A549 cells. Importantly, AGSST-D micelles showed more effective killing activity in A549-bearing mice than GSST-D and DOX⋅HCl. It was revealed that AGSST-D micelles had no obvious systemic toxicity. Overall, AGSST micelles would have the potential to be an effective drug carrier for targeted tumor therapy.

Oxygen-Free Csp3-H Oxidation of Pyridin-2-yl-methanes to Pyridin-2-yl-methanones with Water by Copper Catalysis.

Aromatic ketones are important pharmaceutical intermediates, especially the pyridin-2-yl-methanone motifs. Thus, synthetic methods for these compounds have gained extensive attention in the last few years. Transition metals catalyze the oxidation of Csp3-H for the synthesis of aromatic ketones, which is arresting. Here, we describe an efficient copper-catalyzed synthesis of pyridin-2-yl-methanones from pyridin-2-yl-methanes through a direct Csp3-H oxidation approach with water under mild conditions. Pyridin-2-yl-methanes with aromatic rings, such as substituted benzene, thiophene, thiazole, pyridine, and triazine, undergo the reaction well to obtain the corresponding products in moderate to good yields. Several controlled experiments are operated for the mechanism exploration, indicating that water participates in the oxidation process, and it is the single oxygen source in this transformation. The current work provides new insights for water-involving oxidation reactions.

Ruthenium-Catalyzed Oxidative Synthesis of N-(2-triazine)indoles by C-H Activation.

1,3,5 triazines, especially indole functionalized triazine derivatives, exhibit excellent activities, such as anti-tumor, antibacterial, and anti-inflammatory activities. Traditional methods for the synthesis of N-(2-triazine) indoles suffer from unstable materials and tedious operations. Transition-metal-catalyzed C-C/C-N coupling provides a powerful protocol for the synthesis of indoles by the C-H activation strategy. Here, we report the efficient ruthenium-catalyzed oxidative synthesis of N-(2-triazine) indoles by C-H activation from alkynes and various substituted triazine derivatives in a moderate to good yield, and all of the N-(2-triazine) indoles were characterized by 1H NMR, 13C NMR, and HRMS. This protocol can apply to the gram-scale synthesis of the N-(2-triazine) indole in a moderate yield. Moreover, the reaction is proposed to be performed via a six-membered ruthenacycle (II) intermediate, which suggests that the triazine ring could offer chelation assistance for the formation of N-(2-triazine) indoles.

Synthesis and characterization of a Cu(ii) coordination-containing TAM radical as a nitroxyl probe.

Nitroxyl (HNO) has been identified as an important signaling molecule in biological systems, and it plays critical roles in many physiological processes. However, its detection remains challenging because of the limited sensitivity and/or specificity of existing detection methods. Low-frequency electron paramagnetic resonance (EPR) spectroscopy and imaging, coupled with the use of exogenous paramagnetic probes, have been indispensable techniques for the in vivo measurement of various physiological parameters owing to their specificity, noninvasiveness and good depth of magnetic field penetration in animal tissues. However, the in vivo detection of HNO levels by EPR spectroscopy and imaging is limited due to the need for improved probes. We report the first "turn on-response" EPR probe for HNO utilizing a Cu(ii) coordination-containing TAM radical (denoted as CuII[TD1]). Upon reaction with HNO, CuII[TD1] shows a 16.1-fold turn-on in EPR signal with a low detection limit of 1.95 µM. Moreover, low-temperature EPR spectroscopic and ESI-MS studies showed that the sensing mechanism relies on the reduction of Cu(ii) by HNO. Lastly, CuII[TD1] is selective for HNO over other reactive nitrogen and oxygen species except for some reductants (Cys and Asc). This new Cu(ii) coordination-containing TAM radical shows great potential for in vivo EPR HNO applications in the absence of reducing agents and provides insights into developing improved and targeted EPR HNO probes for biomedical applications.

The copper-catalyzed oxidation of arylmethyl triazines with H2O toward the oxidant-free synthesis of aroyl triazines.

We report an efficient copper-catalyzed dehydrogenation method for the synthesis of aroyl triazines from arylmethyl triazines with water in the absence of additional oxidants or hydrogen acceptors. The use of substrates with both electron-donating and electron-withdrawing groups resulted in moderate to good yields. Using liquid chromatography-mass spectrometry, 18O-labeled-water reactions and hydrogen capture experiments confirmed that water was the only oxygen donor and hydrogen was the by-product. This oxidation strategy provides a new approach for the synthesis of aroyl triazines with a broad substrate scope.

Rapid Screening and Identification of Chemical Constituents From Ophiopogon japonicus by High-Performance Liquid Chromatography Coupled to Electrospray Ionization and Quadrupole Time-of-Flight Mass Spectrometry.

Ophiopogon japonicus (Thunb.) Ker-Gawl (Liliaceae), which is named as "Maidong" in China, is widely used in traditional Chinese medicine for treating fever, cough, inflammation, epistaxis, constipation, respiratory disease and gastrointestinal disorders. However, the systematic analysis of chemical constituents of O. japonicus has not been well established because of the complexity and trace. In this paper, an effective and reliable high-performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry method was successfully developed to separate and identify the chemical constituents from O. japonicus. As a result, a total of 30 compounds including steroidal saponins, homoisoflavonoids, allylbenzene, cholest and cryptomeridiol were screened or tentatively identified. Of them, three new steroidal saponins were found and tentatively characterized in O. japonicus. This study provides a meaningful material basis for further quality control and pharmacological research.

Inhibition of Tumor Growth of Human Hepatocellular Carcinoma HepG2 Cells in a Nude Mouse Xenograft Model by the Total Flavonoids from Arachniodes exilis.

A tumor growth model of human hepatocellular carcinoma HepG2 cells in nude mice was employed to investigate the antitumor activity of the total flavonoids extracted from Arachniodes exilis (TFAE) in vivo. Several biochemical assays including hematoxylin-eosin (HE) staining, immunohistochemistry, and Western blot were performed to elucidate the mechanism of action of total flavonoids extracted from Arachniodes exilis (TFAE). The results showed that TFAE effectively inhibited the tumor growth of hepatocellular carcinoma in nude mice and had no significant effect on body weight, blood system, and functions of liver and kidney. Expression levels of proapoptotic proteins Bax and cleaved caspase-3 remarkably increased while the expressions of Bcl-2, HIF-1α, and VEGF were suppressed by TFAE. These results suggested that the antitumor potential of TFEA was implied by the apoptosis of tumor cells and the inhibition of angiogenesis in tumor tissue.

[Molluscicidal mechanism of combining use of extract of Glycyrrhiza uralensis and niclosamide].

OBJECTIVE: To investigate the molluscicidal mechanism of combining use of the extract of Glycyrrhiza uralensis (GE) and niclosamide (Nic). METHODS: The Oncomelania hupensis snails were immersed in Nic, GE and GE+Nic solutions for 24 h and 48 h respectively, and then were put into fresh water to confirm their survival condition. The alive ones were dissected to obtain their livers. The effects of the drugs on the protein and glycogen of the liver of O. hupensis were observed, and the effects on contractile activity of vola pedis of the snails were studied by the experimental method of isolated smooth muscles of 0. hupensis. RESULTS: GE had no obvious effects on the protein and glycogen in the liver of O. hupensis (all P > 0.05), but it could inhibit the contractions and decrease the contractile frequency of smooth muscles of vola pedis of O. hupensis (all P < 0.05). Nic could significantly decrease the levels of protein and glycogen in the liver of O. hupensis (all P < 0.05) , as well as enhance the contractions and contractile frequencies of smooth muscles of vola pedis of O. hupensis (P < 0.05). GE combined with Nic could further decrease the levels of protein and glycogen in the liver of O. hupensis (all P < 0.05), meanwhile, it could inhibit the contractions and decrease the contractile frequency of smooth muscles of vola pedis of O. hupensis (all P < 0.05). CONCLUSIONS: The combining use of GE and Nic can accelerate the liver damage of O. hupensis, and also can inhibit the contractions of smooth muscles of vola pedis of O. hupensis which increases the contacting time of the drug, thus leads to the synergism of molluscicidal effect.

32k Da protein improve ovariectomy-induced bone loss in rats.

The objective of the present study was to systematically explore the effects of 32K Da protein (32KP) on postmenopausal osteoporosis. Eighty 3-mo-old female Sprague-Dawley rats were employed and randomly divided into one sham-operated group (SHAM) and five ovariectomy (OVX) subgroups as OVX (control), OVX with 17-ethinylestradiol (E2, 25 g/kg/day), OVX with 32KP of graded doses (50, 50, or 150 mg/kg/day). 32KP or E2 diet was fed on week 4 after operation, for 16 weeks. Bone mass, bone turnover and strength were evaluated by dual-energy X-ray absorptiometry (DEXA), biochemical markers and three-point bending test, respectively. Femur marrow cavity was observed by light microscopy via hematoxylin-eosin staining. It is observed that different dosage treatment of 32KP increased the body weight and prevented the loss of bone mass induced by OVX. The prevention effect against bone loss was presumably due to the altering of the rate of bone remodeling. The bone mineral density and bone calcium content in OVX rats were lower than that in the control group, suggesting that 32KP was able to prevent significant bone loss. In addition, the data from three point bending test and femur sections showed that 32KP treatment enhanced bone strength and reduced the marrow cavity of the femur in OVX rats. In the serum and urine assay, 32KP decreased urinary deoxypyridinoline and calcium concentrations; however, serum alkaline phosphatase activities were not inhibited. It suggested that amelioration of bone loss was changed via inhibition of bone reabsorption. Our findings indicated that 32KP might be a potential alternative drug for the prevention and treatment of postmenopausal osteoporosis.

Fabrication and characterization of nuclear localization signal-conjugated glycol chitosan micelles for improving the nuclear delivery of doxorubicin.

BACKGROUND: Supramolecular micelles as drug-delivery vehicles are generally unable to enter the nucleus of nondividing cells. In the work reported here, nuclear localization signal (NLS)-modified polymeric micelles were studied with the aim of improving nuclear drug delivery. METHODS: In this research, cholesterol-modified glycol chitosan (CHGC) was synthesized. NLS-conjugated CHGC (NCHGC) was synthesized and characterized using proton nuclear magnetic resonance spectroscopy, dynamic light scattering, and fluorescence spectroscopy. Doxorubicin (DOX), an anticancer drug with an intracellular site of action in the nucleus, was chosen as a model drug. DOX-loaded micelles were prepared by an emulsion/solvent evaporation method. The cellular uptake of different DOX formulations was analyzed by flow cytometry and confocal laser scanning microscopy. The cytotoxicity of blank micelles, free DOX, and DOX-loaded micelles in vitro was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in HeLa and HepG2 cells. RESULTS: The degree of substitution was 5.9 cholesterol and 3.8 NLS groups per 100 sugar residues of the NCHGC conjugate. The critical aggregation concentration of the NCHGC micelles in aqueous solution was 0.0209 mg/mL. The DOX-loaded NCHGC (DNCHGC) micelles were observed as being almost spherical in shape under transmission electron microscopy, and the size was determined as 248 nm by dynamic light scattering. The DOX-loading content of the DNCHGC micelles was 10.1%. The DOX-loaded micelles showed slow drug-release behavior within 72 hours in vitro. The DNCHGC micelles exhibited greater cellular uptake and higher amounts of DOX in the nuclei of HeLa cells than free DOX and DOX-loaded CHGC (DCHGC) micelles. The half maximal inhibitory concentration (IC(50)) values of free DOX, DCHGC, and DNCHGC micelles against HepG2 cells were 4.063, 0.591, and 0.171 µg/mL, respectively. Moreover, the IC(50) values of free DOX (3.210 µg/mL) and the DCHGC micelles (1.413 µg/mL) against HeLa cells were nearly 6.96- and 3.07-fold (P < 0.01), respectively, higher than the IC(50) value of the DNCHGC micelles (0.461 µg/mL). CONCLUSION: The results of this study suggest that novel NCHGC micelles could be a potential carrier for nucleus-targeting delivery.

Development and validation of a high-performance liquid chromatographic method for the determination of stemoninine in rat plasma after administration of Stemona tuberosa extracts.

For the first time, an HPLC method was developed and validated for the determination of stemoninine in plasma after oral and intravenous administration of the extract of the roots of Stemona tuberosa to rats. Plasma samples were analyzed on a Waters reversed-phase C(18) column using a gradient mobile-phase of eluent A (water containing 0.1% formic acid and 0.2% triethylamine, pH 3.68) and eluent B (acetonitrile-water, 50:50, v/v). The flow rate was 1.0 mL/min and the detector wavelength was 210 nm. The Waters Oasis solid-phase extraction cartridge was applied for the preparation of plasma samples with high recovery. A good linear relationship was obtained in the concentration range of 1.55-124 µg/mL (r = 0.9995). The limits of quantification and detection were 1.55 and 0.42 µg/mL, respectively. The average recoveries ranged from 91.11 to 96.43% in plasma at stemoninine concentrations of 3.10, 62.0 and 99.2 µg/mL. Intra- and inter-batch coefficient of variations were 3.27-5.37% and 2.49-3.92%, respectively. This method was successfully applied to pharmacokinetic studies after oral and intravenous administration of Stemona tuberosa extract in rats.

[Elementary exploration of the origin and development of marine Chinese materia medica].

According to archaeological discoveries, humans began to make use of marine natural resources early in the Palaeolithic era. In the Spring and Autumn period and Warring States period, they began to use marine life as medicines and also had simple cognitions on their efficacy and processing. In the Qin and Han dynasties, people further deepened the understanding of the marine Chinese materia medica and created prescriptions making use of marine drugs. In the Tang and Song period, the number of marine Chinese materia medica species and corresponding prescriptions apparently increased. The cognitions of the property, flavor, efficacy as well as the compatible principle of marine Chinese materia medica was further deepened and the scope of their treatment also significantly expanded. In the Ming and Qing dynasties, the cognition of the marine Chinese materia medica was mainly the conclusions of the previous experience. After the founding of the People's Republic of China (PRC), with the development of science and technologies, the ability of exploiting and utilizing the marine Chinese materia medica by people dramatically increased, and the species of marine Chinese materia medica reached more than one thousand. However, the development of marine Chinese materia medica is confronted with new problems; although the number of species of marine Chinese materia medica increased, the understanding of their property and flavor is obviously lagging behind, which seriously affects the clinical application of marine Chinese materia medica.