Latest ArticlesThe three-component reaction of triphenylphosphine, dimethyl hex-2-en-4-ynedioate and arylidene N, N'-dimethylbarbituric acids in dry methylene dichloride at room temperature afforded trans-1, 3-disubstituted 7, 9-diazaspiro[4.5]dec-1-enes in good yields and with high diastereoselectivity. However, the similar three-component reaction with arylidene Meldrum acids resulted in a mixtures of cis/trans-1, 2-disubstituted 7, 9-dioxaspiro[4.5]dec-1-enes. Additionally, the three-component reaction of triphenylphosphine, dimethyl but-2-ynedioate and arylidene Meldrum acids gave polysubstituted 5-(triphenyl-λ5-phosphanylidene)cyclopenta-1, 3-dienes. A plausible reaction mechanism was proposed for the formation of various products with different regioselectivity and diastereoselectivity.
Cancer therapy with nanoscale drug formulations has made significant progress in the past few decades. However, the selective accumulation and release of therapeutic agents in the lesion sites are still great challenges. To this end, we developed a cRGD-decorated pH-responsive polyion complex (PIC) micelle for intracellular targeted delivery of doxorubicin (DOX) to upregulate tumor inhibition and reduce toxicity. The PIC micelle was self-assembled via the electrostatic interaction between the positively charged cRGD-modified poly(ethylene glycol)-block-poly(L-lysine) and the anionic acid-sensitive 2, 3-dimethylmaleic anhydride-modified doxorubicin (DAD). The decoration of cRGD enhanced the cell internalization of PIC micelle through the specific recognition of αvβ3 integrin on the membrane of tumor cells. The active DOX was released under intracellular acidic microenvironment after endocytosis following the decomposition of DAD. Moreover, the targeted PIC micelle exhibited enhanced inhibition efficacies toward hepatoma in vitro and in vivo compared with the insensitive controls. The smart multifunctional micelle provides a promising platform for target intracellular delivery of therapeutic agent in cancer therapy.
Nanomaterials as drug carriers hold promise for the treatment of carcinomas, but integrating multiple functions into a single vector is difficult. In this study, we aim to develop efficient materials as vectors for co-delivery of microRNA-122 (miR-122) and sorafenib (SRF). We successfully synthesized amphiphilic galactose-modified PEGylated poly(amino-co-ester) (Gal-PEG-PPMS) copolymers consisted of hydrophilic Gal-PEG5k chain segments and hydrophobic poly(ω-pentadecalactone-co-N-methyldiethyleneamine-co-sebacic acid) chain segments, which self-assembled to form cationic micelles at pH 5.2. The results showed that the micelles could encapsulate SRF and bind miR122 simultaneously, increase cellular uptake efficiency. Furthermore, the micelles showed favorable transfection efficiency in enhancing miR122 expression level, the migration and invasion ability of hepatocellular carcinoma (HCC) cells were significantly inhibited after being transfected with miR122-loaded micelles. Most importantly, the co-delivery micelles decreased cell activities of HepG2 cells, which was more effective than miR122 or SRF loaded micelles alone. Collectively, Gal-PEG-PPMS nanoparticles are promising multifunctional carriers for miR122 and SRF co-delivery system to treat HCC.
We herein propose a co-delivery approach where small interference RNA (siRNA) and anticancer chemotherapeutic drug are simultaneously loaded into a single delivery carrier for the combined treatment of breast cancer and metastasis prevention. The co-delivery vector is composed of chondroitin sulfate (CS)-coated β-cyclodextrin-polyethylenemine polymer, which is capable of loading paclitaxel (PTX) and siRNA simultaneously to form therapeutic nanocomplexes. The nanocomplex, termed as CPPTX-siCD146-CS, is demonstrated to have strong active targeting ability towards CD44-overexpresing breast cancer cells. Moreover, the co-delivery of PTX and siRNA not only effectively inhibits cancer cells proliferation and induces apoptosis, but also well prevents metastasis. Importantly, CP-PTX-siCD146-CS nanocomplexes exhibit stronger cytotoxic effects and anti-metastatic effects on MBA-MD-231 breast cancer cells, in comparison with PTX or siCD146 mono-treatment. The current study defines a potential therapeutic strategy for the combined breast cancer treatment and metastasis prevention from a codelivery perspective.
A new simple bifunctional chemosensor 1 based on rhodamine was synthesized by hydrazide and formylformic acid, which could detect Cu2+ and Hg2+ via different detecting methods in CH3CN-HEPES buffer solution (20 mmol/L, pH 7.4) (1:9, v/v) respectively. When sensor 1 bound with Cu2+, it showed a colorimetric change, while a selective enhancement in fluorescence occurred upon 1 binding with Hg2+, resulting from the spirolatam-ring opening process. The binding modes of 1 with Cu2+ and Hg2+ were investigated based on UV, fluorescence change, ESI-Mass and Job's Plot data. Moreover, sensor 1 could selectively detect target ion in a mixed solution of Cu2+ and Hg2+, and the two metal ions do not interfere with each other in the process of detecting Cu2+ or Hg2+ with 1.
Insect chitinase and N-acetyl-β-D-hexosaminidases (Hex) are potential targets for developing new pesticides. Here, a series of thiazolylhydrazones I (with substituted group R1 at N3) and II (with substituted group R1 at N2) were designed, synthesised and evaluated as competitive inhibitors of OfHex1 and OfChi-h, from the agricultural pest Ostrinia furnacalis. Derivatives I-3d and II-3d, with phenoxyethyl group at R1, demonstrated the best inhibitory activities against OfHex1 and OfChi-h. Molecular docking analysis indicated that the branched conformation compound II-3d (Ki=1.5 μmol/L) formed more hydrogen bonds with OfHex1 than the stretched conformation compound I-3d (Ki=5.9 μmol/L). The differences in compounds' binding conformations with OfChi-h explained differences in inhibitory activity of compounds I-3d (Ki=1.9 μmol/L) and II-3d (Ki=4.1 μmol/L). This work suggests a novel scaffold for developing specific Hex and Chi-h inhibitors.
Non-nerve cell-derived extracellular matrix (ECM) was coated on the aligned porous polypyrrole-poly(L-lactide) (PPy-PLLA) fiber-films with the conductivity of ~12 mS/m via L929 cells culture and lysing, resulting in~10% increase of PC12 cells attachment and 26 μm increase of neurites length. The neurite length of ~149 μm in EGF/NGF group (optimal concentration radio of 12.5/50 (ng/mL)) on aligned and ECM-conjugated fiber-films was significantly larger than ~94 μm in only NGF group (50 ng/mL), confirming the synergy of EGF, NGF and aligned ECM-conjuaged PPy-PLLA fibers. When differentiated PC12 cells were exerted electrical stimulation (ES) of 100 mV/cm for 4 h/day in 2 day through ECM-PPyPLLA fiber-films, their neurite length reached to ~251 μm, significantly larger than ~149 μm of group without ES, due to the higer expression of related neural proteins in ES group. A simple mechanism was proposed to analyze synergistical effect of ECM, EGF, NGF on axons adhesion and elongation along the aligned ECM-coated fibers under ES condition.
Dracomolphesin A-E (1-5), five 3, 4-seco-phenylpropanoids featuring an aromatic ring opened framework, were isolated from the aerial parts of Dracocephalum moldavica. The structures with absolute configurations were determined by spectroscopic methods coupled with Mosher method. Notably, these compounds represented an example of aromatic ring cleavage products of phenylpropanoids. The possible biosynthetic pathway of these compounds was proposed. Compounds 1, 2, 4 and 5 were demonstrated to be Nrf2 pathway activators.
(+)-6-3'a, 7-6'-Isowallichilide and (-)-6-3'a, 7-6'-isowallichilide, a pair of enantiomeric phthalide dimers featuring new 6-3'a, 7-6' dimerization sites, were isolated from Ligusticum chuanxiong. The structures were elucidated by NMR spectroscopy and X-ray diffraction analysis. Furthermore, the absolute configurations were assigned using experimental and theoretical electronic circular dichroism methods. Their nitric oxide inhibition, antiplatelet aggregation and antioxidant activities were investigated.
Herein, we firstly developed a non-covalent glycosylated gold nanoparticles/peptides nanovaccine which is assembled by β-cyclodextrin (β-CD) based host-guest recognitions. This nanovaccine can generate significant titers of antibodies and improve the therapeutic effect against melanoma, suggesting the immunogenicity of peptide antigens can be improved by loading with this carrier. The novel vaccine carrier provides a platform for the transport of various antigens especially T cell-independent antigens.