The critical size of gold nanoparticles for overcoming P-gp mediated multidrug resistance.

Multidrug resistance (MDR) remains a huge obstacle during cancer treatment. One of the most studied MDR mechanisms is P-glycoprotein (P-gp) mediated drug efflux. Based on the three-dimensional structural characteristics of P-gp, gold nanoparticles (AuNPs) with average sizes of 4.

Gold Nanorods Functionalized with Cathepsin B Targeting Peptide and Doxorubicin for Combinatorial Therapy against Multidrug Resistance.

Multidrug resistance (MDR) and adverse effects of chemotherapeutic agents are severe issues in clinical cancer treatment. Due to the dysregulation of enzymes in the cancer cells, enzyme-responsive drug delivery systems (DDSs) have been considered as a viable technology for cancer chemotherapy. In the present work, doxorubicin (DOX) is visible after leaving from AuNR-LAX.

Constraining the conformation of peptides with Au nanorods to construct multifunctional therapeutic agents with targeting, imaging, and photothermal abilities.

We demonstrated an easy-to-use strategy, instead of the tedious cyclization of the peptide backbone, to constrain the freedom of an RGD (arginine, glycine, aspartic acid) sequence with gold nanorods. We further constructed a multifunctional therapeutic agent which showed targeting, application in two-photon photoluminescence imaging, and near-infrared photothermal ability, suggesting the potential of this novel strategy in the development of RGD-containing drugs for biomedical applications.

Synthesis of a Novel Fluorescent Ruthenium Complex with an Appended Ac₄GlcNAc Moiety by Click Reaction.

The -linked β--acetylglucosamine (-GlcNAc) modification is an abundant post-translational modification in eukaryotic cells, which plays a fundamental role in the activity of many cells and is associated with pathologies like type II diabetes, Alzheimer’s disease or some cancers. However, the precise connexion between -GlcNAc-modified proteins and their function in cells is largely undefined for most cases. Confocal microscopy is a powerful and effective tool for in-cell elucidation of the function of biological molecules.

Schiff base derived from thiosemicarbazone and anthracene showed high potential in overcoming multidrug resistance in vitro with low drug resistance index.

Multidrug resistance (MDR) is a huge obstacle in cancer chemotherapeutics. Overcoming MDR is a great challenge for anticancer drug discovery. Here, DNA binding and cytotoxicity of Schiff base L1 and L2 were explored to assess their efficiency in fighting cancer and overcoming the MDR.

TAT-Modified Gold Nanoparticle Carrier with Enhanced Anticancer Activity and Size Effect on Overcoming Multidrug Resistance.

Highly efficient targeted delivery is crucial for successful anticancer chemotherapy. In this study, we developed a drug delivery system ANS-TAT-AuNP that loads anticancer molecule 2-(9-anthracenylmethylene)-hydrazinecarbothioamide (ANS) via conjugation with cell-penetrating peptide TAT modified AuNPs. The in vitro study showed that the IC value of ANS-TAT-AuNPs reduced by 11.

Evaluating p97 inhibitor analogues for their domain selectivity and potency against the p97-p47 complex.

We previously found that p97 ATPase inhibitors 2-(2-amino-1H-benzo[d]imidazol-1-yl)-N-benzyl-8-methoxyquinazolin-4-amine (ML240) and 2-(2H-benzo[b][1,4]oxazin-4(3H)-yl)-N-benzyl-5,6,7,8-tetrahydroquinazolin-4-amine (ML241) specifically target the D2 domain of wild-type p97. In addition, one of the major p97 cofactors, p47, decreases their potencies by ∼50-fold. In contrast, N(2) ,N(4) -dibenzylquinazoline-2,4-diamine (DBeQ) targets both the D1 and D2 domains and shows only a four- to sixfold decrease in potency against the p97-p47 complex.

Hydrogen sulfide as an endogenous modulator in mitochondria and mitochondria dysfunction.

Hydrogen sulfide (H(2)S) has historically been considered to be a toxic gas, an environmental and occupational hazard. However, with the discovery of its presence and enzymatic production through precursors of L-cysteine and homocysteine in mammalian tissues, H(2)S has recently received much interest as a physiological signaling molecule. H(2)S is a gaseous messenger molecule that has been implicated in various physiological and pathological processes in mammals, including vascular relaxation, angiogenesis, and the function of ion channels, ischemia/reperfusion (I/R), and heart injury.

Effects of thioperamide on seizure development and memory impairment induced by pentylenetetrazole-kindling epilepsy in rats.

Background: Histamine H(3) receptor antagonists have been considered as potential drugs to treat central nervous system diseases. However, whether these drugs can inhibit epileptogenesis remains unclear. This study aimed to investigate the effects of thioperamide, a selective and potent histamine H(3) receptor antagonist, on the seizure development and memory impairment induced by pentylenetetrazole (PTZ)-kindling epilepsy in rats.

Chelating Schiff base assisted azide-bridged Mn(II), Ni(II) and Cu(II) magnetic coordination polymers.

Four new Mn(II), Ni(II) and Cu(II) coordination polymers [Mn2(L1)(μ(1,1)-N3)2(μ(1,3)-N3)2]n (1), [Ni(L2)2(μ(1,3)-N3)]n(ClO4)n (2), [Cu(L3)(μ(1,1)-N3)(N3)]n (3) and [Cu(L4)(μ(1,1)-N3)2]n (4) (L1 = N,N′-bis(2-pyridylmethylene)ethane-1,2-diamine, L2 = N-(2-pyridylmethylene)methylamine, L3 = N-(2-pyridylmethylene)-3-pyridylamine, L4 = N-(2-pyridylmethylene)-tbutylamine) have been synthesized and characterized by single-crystal X-ray analysis and magnetic measurements. Complex 1 indicates a stoichiometry-dependent structural change (based on Mn:L1:N3 = 2:1:4 molar ratio) and consists of two-dimensional (2-D) (4,4) net layers, in which Mn(II) centers are co-bridged by single end-to-end (EE), double end-on (EO) azide and chelate-bridging L1 ligands. Complex 2 shows a single EE azide-bridged one-dimensional (1-D) Ni(II) chain.

2:1 multiplexing function in a simple molecular system.

1-[(Anthracen-9-yl)methylene] thiosemicarbazide shows weak fluorescence due to a photo-induced electron transfer (PET) process from the thiosemicarbazide moiety to the excited anthracene. The anthracene emission can be recovered via protonation of the amine as the protonated aminomethylene as an electron-withdrawing group that suppresses the PET process. Similarly, chelation between the ligand and the metal ions can also suppress the PET process and results in a fluorescence enhancement (CHEF).

The intracellular controlled release from bioresponsive mesoporous silica with folate as both targeting and capping agent.

A smart mesoporous silica nanocarrier with intracellular controlled release is fabricated, with folic acid as dual-functional targeting and capping agent. The folate not only improves the efficiency of the nanocarrier internalized by the cancer cells, but also blocks the pores of the mesoporous silica to eliminate premature leakage of the drug. With disulfide bonds as linkers to attach the dual-functional folate within the surface of mesoporous silica, the controlled release can be triggered in the presence of reductant dithiothreitol (DTT) or glutathione (GSH).

Logic information communication in a fluorescent molecular switch.

Based on the chemical-sensitive fluorescence emission behaviors of the molecular switch 4-bromo-5-methoxy-2-(2-pyridyl)thiazole (2-BMPT), the communication of logic information between two functional units has been realized. With the rational control of the protonation and coordination reaction of 2-BMPT, an upstream switching unit (a 1:2 demultiplexer) and two downstream data-processing units are involved and interconnected in the communication. The two output states of the 1:2 demultiplexer serve as the initial input states of the two parallel downstream data-processing units, which execute the information communication between the two circuit layers.

Intramolecular charge transfer in 5-methoxy-2-(2-pyridyl)thiazole-derived fluorescent molecules with different acceptor or donor substituents.

On the basis of the rational derivation of 5-methoxy-2-(2-pyridyl)thiazole (2-MPT), we synthesized a new series of charge-transfer-based fluorescent molecules bearing different electronic donors or acceptors. The substituents range from strong electronic donors (e.g.

Orientational organization of organic semiconductors within periodic nanoscale silica channels: modification of fluorophore photophysics through hierarchical self-assembly.

Smart nanomaterials: The orientational organization of small organic semiconductors (anthracene, in this case) within periodic nanoscale silica channels (see figure) is achieved through a novel hierarchical self-assembly approach. This elicits interesting optical effects and improved mechanical properties that could be of potential importance for functional materials.A novel hierarchical organic-inorganic self-assembly approach is proposed in driving the orientational organization of small organic semiconductors (anthracene, in this case).

Supramolecular engineering of a 2D Kagomé lattice: synthesis, structures, and magnetic properties.

Two 2D Mn (II) complexes, [Mn3(TzDC)2(phen)3] x 2 H2O (1; H3TzDC = 1,2,3-triazole-4,5-dicarboxylic acid, phen = 1,10-phenanthroline) and [Mn3(TzDC)2(bipy)3] x 4 H2O (2; bipy = 2,2'-bipyridine), were synthesized by hydrothermal reactions and characterized magnetically, and complex 1 was the first example of the chiral complex with a Kagomé lattice connectivity obtained through spontaneous resolution.

A fluorescent-switch-based computing platform in defending information risk.

A molecular computing platform to defend against illegal information theft and invasion is obtained by the rational control of chemical reaction sequences in a newly prepared multiswitchable fluorophore 2-(4-aminophenylethylyl)-5-methoxy-2-(2-pyridyl)thiazole. Some of the fluorescent states with distinct recognition features are only activated through input-sequence-sensitive conversions. Chemically encoded user identity information can then be transmitted from a sequential logic unit to a combinational logic circuit, and hence, result in user-specific digital functionalities.

A novel three-dimensional heterometallic compound: templated assembly of the unprecedented planar "Na within [Cu4]" metalloporphyrin-like subunits.

A 3D heterometallic compound, [Cu4Na4(TzDC)4(H2O)7]n (H3TzDC = 1,2,3-triazole-4,5-dicarboxylic acid), which contains unprecedented planar "Na within [Cu4]" metalloporphyrin-like subunits, was synthesized by hydrothermal reactions involving in situ formation of the ligand and templated assembly of the metalloporphyrin-like subunits.

Infrared and electronic spectra of copper (II) complex of maleonitriledithiolate and 4,4'-dimethyl-2, 2'-bipyridine and their theoretical studies.

The molecular structure and binding, as well as infrared and electronic spectroscopic properties for the title complex Cu(mnt)(dmbpy)(mnt(2-)=maleonitriledithiolate, dmbpy=4,4'-dimethyl-2,2'-bipyridine) were studied in this paper. With semi-empirical PM3 and non-empirical DFT (B3LYP/6-311G*) methods, the molecular geometry of the complex was optimized and corresponding vibrational spectra in the gaseous state were obtained. The calculated results derived from DFT were more reasonable than those from PM3.

Spectroscopic and theoretical studies on nickel(II) complex of maleonitriledithiolate and 2,2'-bipyridine.

The complete IR spectra of the title complex Ni(mnt)(bpy) (mnt=maleonitriledithiolate, bpy=2,2'-bipyridine) and a new method to analyze vibrational spectra for such a complicated metal complex are reported in this paper. The molecular geometry, binding, electronic structure and spectroscopic property of it have been studied in detail by theoretical calculations. The geometry optimization from PM3 calculations give that this molecule is of a planar structure with the symmetry point group C(2v) and its ground state is the spin triplet state.