Controlling the Emissive, Chiroptical, and Electrochemical Properties of Double [7] Helicenes through Embedded Aromatic Rings.

We present here the synthesis and in-depth physicochemical characterization of a double hetero[7]helicene fused with four triazole rings at both helical ends. The comparison of this triazole-fused double helicene with the previously reported all-carbon and thiadiazole-fused analogs revealed the huge impact of the embedded aromatic rings on the photophysical features. The small structural variation of the terminal rings from thiadiazole to triazole caused a dramatic change of the photoluminescence quantum yields (PLQYs) from <1 % to 96 %, while the replacement of the terminal benzene rings with triazole rings induced a tenfold enhancement of the circularly polarized luminescence dissymmetry factor. These observations were well corroborated with transient absorption analysis and/or theoretic calculations. In addition, the triazole-fused double helicene exhibited ambipolar redox behavior, enabling the generation of radical cation and anion species by electrochemical and chemical methods and showing its potential for spin-related applications.

Metformin impairs the growth of liver kinase B1-intact cervical cancer cells.

OBJECTIVE: Metformin is one of the most widely used drugs for the treatment of type 2 diabetes. Recent investigations demonstrated that application of metformin reduces cancer risk. The present study aimed to determine the role of liver kinase B1 (LKB1) in the response of cervical cancer cells to metformin. METHODS: LKB1 expression and the integrity of LKB1-AMPK signaling were determined with immunoblot in 6 cervical cancer cell lines. Cellular sensitivity to metformin was analyzed with MTT assay. RESULTS: Metformin inhibited growth of cervical cancer cells, C33A, Me180, and CaSki, but was less effective against HeLa, HT-3, and MS751 cells. Analyzing the expression status and the integrity of LKB1-AMPK-mTOR signaling, we found that cervical cancer cells sensitive to metformin were LKB1 intact and exerted an integral AMPK-mTOR signaling response after the treatment. Ectopic expression of LKB1 with stable transduction system or inducible expression construct in endogenous LKB1 deficient cells improved the activation of AMPK, promoted the inhibition of mTOR, and prompted the sensitivity of cells to metformin. In contrast, knock-down of LKB1 compromised cellular response to metformin. Our further investigation demonstrated that metformin could induce both apoptosis and autophagy in cervical cancer cells when LKB1 is expressed. CONCLUSIONS: Metformin is a potential drug for the treatment of cervical cancers, in particular to those with intact LKB1 expression. Administration of cell metabolism agonists may enhance LKB1 tumor suppression, inhibit cell growth, and reduce tumor cell viability via the activation of LKB1-AMPK signaling.

X-shaped thiadiazole-containing double [7]heterohelicene with strong chiroptical response and π-stacked homochiral assembly.

An X-shaped double [7]heterohelicene 1 bearing four thiadiazole units is synthesized by regioselective cyclodehydrogenation. Enantiopure 1 exhibits excellent chiroptical properties with an impressive absorption dissymmetry factor of up to 0.027, as well as a compact π-stacked homochiral assembly which is unprecedented in the realm of double helicenes.

Possible magnetic multifunctional nanoplatforms in medicine.

Recently, magnetic nanoparticles have attracted attention because of their potential in biomedicine. They can be applied to special medical techniques, such as separation, immunoassay, magnetic resonance imaging (MRI), drug delivery, and hyperthermia, and so on. But these nanoparticles only have one or two kinds of functions and cannot realize multipurpose. Therefore, we propose that it is need to constitute magnetic multifunctional nanoplatforms, which not only have delivery property of gene vector and drug carrier, but also have heating property of thermseeds in the alternative magnetic field. Recent trials have proved that gene therapy combined with chemotherapy and hyperthermia achieves better results than single therapy strategy. But this is difficult in clinical practice. With the development of the magnetic multifunctional nanoplatforms, the combined treatment is feasible in clinical practice. This nanoplatforms is versatile, and can be applied to wide fields. The use of magnetic multifunctional nanoplatforms will further improve medical techniques.

[Mechanism of hepatocyte transformation by HCV NS3 using two-dimensional electrophoresis and mass spectrometry].

OBJECTIVE: To investigate the proteome of hepatocyte transformation by hepatitis C virus (HCV) nonstructural protein 3 (NS3). METHODS: Human hepatocyte line QSG7701 stably expressing HCV NS3 C-terminal deleted protein was constructed, which was named pRcHCNS3/QSG. Two-dimensional electrophoresis (2-DE) was used to separate the total protein of pRcHCNS3/QSG and pRcCMV transfected cells (pRcCMV/QSG) respectively. Differentially expressed protein spots were identified by mass spectrometry. Western blot confirmed the differentially expressed proteins. RESULTS: 2-DE profiles with high resolution and reproducibility were obtained. The average spots of pRcHCNS3/QSG and pRcCMV/QSG were (1183+/-77) and (1095+/-82) respectively, and (920+/-60) spots were matched. Twenty-one differentially expressed protein spots were chosen randomly and 15 were identified by mass spectrometry. Some proteins such as Ras, P38 and HD53 which were involved in signal transduction were increased in pRcHCNS3/QSG cells. Western blot also showed strong expression of phosphorylated P44/42 and P38 in pRcHCNS3/QSG cells. Other differentially expressed proteins were related to cell cycle regulation, immunoreaction, tumor invasion and metastasis, and liver metabolizability. CONCLUSION: HCV NS3 might be involved in cell malignant transformation through affecting protein expression and signal transduction such as MAPK cascade. Further study on the signal transductions and their relationship would not only be helpful to explore the mechanism of HCV related HCC, but also provide a new idea for the molecular treatment of HCC.

Effect of Fluorine Substitution on Photovoltaic Properties of Alkoxyphenyl Substituted Benzo[1,2-b:4,5-b']dithiophene-Based Small Molecules.

Two new small molecules, C3T-BDTP and C3T-BDTP-F with alkoxyphenyl-substituted benzo[1,2-b:4,5-b']dithiophene (BDT) and meta-fluorinated-alkoxyphenyl-substituted BDT as the central donor blocks, respectively, have been synthesized and used as donor materials in organic solar cells (OSCs). With the addition of 0.4% v/v 1,8-diiodooctane (DIO), the blend of C3T-BDTP-F/PC71BM showed a higher hole mobility of 8.67 × 10(-4) cm(2) V(-1) s(-1) compared to that of the blend of C3T-BDTP/PC71BM. Two types of interlayers, zirconium acetylacetonate (ZrAcac) and perylene diimide (PDI) derivatives (PDINO and PDIN), were used to further optimize the performance of OSCs. With a device structure of ITO/PEDOT:PSS/donor:PC71BM/PDIN/Al, the OSCs based on C3T-BDTP delivered a satisfying power conversion efficiency (PCE) of 5.27% with an open circuit voltage (V(oc)) of 0.91 V, whereas the devices based on C3T-BDTP-F showed an enhanced PCE of 5.42% with a higher V(oc) of 0.97 V.

Novel amino-modified silica nanoparticles as efficient vector for hepatocellular carcinoma gene therapy.

Due to the ineffective conventional treatment for hepatocellular carcinoma (HCC), the nonviral gene delivery system has been proved to be an attractive alternative to HCC therapy. In this work, we have developed a kind of new self-assembled nanoparticles, which were named as amino-modified silica nanoparticles (AMSNs). Scanning electron microscopy and zeta potential results demonstrated that AMSNs had a diameter of 20-30 nm and positive surface charges of +11.3 mV, respectively. The AMSNs could bind DNA strongly and protect DNA from degradation, which was confirmed by DNA-binding assay and serum protection assay. Furthermore, AMSNs could transfer foreign DNA into targeted cells with high transfection efficiency and little cytotoxicity. Combined with the p53 gene, AMSNs could transfect pp53-EGFP in HepG2 cells and result in a high-level of p53 mRNA and protein expressions. The nude mice treated with AMSNs/pp53-EGFP complexes showed significant tumor growth inhibition. Our results showed the AMSNs, an efficient gene vector, had the potential of gene therapy for HCC.

Differentiation of dried sea cucumber products from different geographical areas by surface desorption atmospheric pressure chemical ionization mass spectrometry.

Without any sample pretreatment, mass spectral fingerprints of 486 dried sea cucumber slices were rapidly recorded in the mass range of m/z 50-800 by using surface desorption atmospheric pressure chemical ionization mass spectrometry (DAPCI-MS). A set of 162 individual sea cucumbers (Apostichopus japonicus Selenka) grown up in 3 different geographical regions (Weihai: 59 individuals, 177 slices; Yantai: 53 individuals, 159 slices; Dalian: 50 individuals, 150 slices;) in north China sea were successfully differentiated according to their habitats both by Principal Components Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA) of the mass spectral raw data, demonstrating that DAPCI-MS is a practically convenient tool for high-throughput differentiation of sea cucumber products. It has been found that the difference between the body wall tissue and the epidermal tissue is heavily dependent on the habitats. The experimental data also show that the roughness of the sample surface contributes to the variance of the signal levels in a certain extent, but such variance does not fail the differentiation of the dried sea cucumber samples.

Cell transformation and proteome alteration in QSG7701 cells transfected with hepatitis C virus non-structural protein 3.

Persistent hepatitis C virus (HCV) infection can cause liver cirrhosis and hepatocellular carcinoma. Non-structural protein 3 (NS3), an important part of HCV, has been implicated in the life cycle of the virus and interacts with host cellular proteins. In this study, we investigated the effect of NS3 protein on cell tranformation and related protein alteration in human hepatocyte QSG7701 cells. The results indicated that stable expression of the NS3 protein in QSG7701 cells induced transformed characters with reduced population doubling time, anchorage-independent growth and tumor development. Fifteen differentially-expressed proteins were separated and identified using 2-D electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry. Western blot analysis confirmed that the increase of phospho-p44/42 and phospho-p38 proteins was associated with transformed cells. These results supported the view that HCV NS3 protein plays a transforming role and provided some clues to elucidate the carcinogenesis mechanism of HCV-related hepatocellular carcinoma.