Highly efficient and recyclable water-soluble fullerene-supported PdCl2 nanocatalyst in Suzuki-Miyaura cross-coupling reaction.

A water-soluble fullerene-supported PdCl2 nanocatalyst [C60-TEGS/PdCl2] was prepared by coordination of water-soluble fullerene nanoparticles with palladium chloride. In pure water, the catalytic activity of nanocatalyst [C60-TEGS/PdCl2] for Suzuki-Miyaura cross-coupling reaction was investigated under different reaction conditions. The results showed that biphenyl compounds could be synthesized in high yields at room temperature using 0.01 mol% of [C60-TEGS/PdCl2] as the catalyst and K2CO3 as the base with the reaction time of 4 h. The catalyst was recycled five times, and the yield clearly did not decrease.

Controlled Dual Drug Release and In Vitro Cytotoxicity of Electrospun Poly(lactic-co-glycolic acid) Nanofibers Encapsulated with Micelles.

In order to realize controlled dual release of two hydrophobic drugs with distinct rates in a vehicle, novel poly(lactic-co-glycolic acid) (PLGA) composite nanofibers encapsulated with micelles were successfully fabricated by "emulsion-electrospinning." Brefeldin A (BFA) was firstly embedded in monomethoxy-poly(ethylene glycol)-b-poly(L-lactide) (MePEG-PLLA) micelles. By means of "emulsion-electrospinning," paclitaxel (PTX) and polymeric micelles contained BFA were successfully loaded into the electrospun PLGA composite nanofibers. The in vitro release results demonstrated that the location of the drugs in the electrospun fibers determined their release profiles. BFA had a long-term and sustained release while PTX had a relatively rapid release in the dual drugs delivery system. In vitro cytotoxicity studies revealed that the composite nanofibers with two drugs restrained HepG-2 cells more efficiently. These results strongly suggested that the electrospun composite nanofibers containing polymeric micelles can be used as an effective controlled dual release of hydrophobic drugs and were suitable for postoperative chemotherapy of cancers.

Fabrication of water-dispersible and biocompatible red fluorescent organic nanoparticles via PEGylation of aggregate induced emission enhancement dye and their cell imaging applications.

PEGylated red fluorescent organic nanoparticles (FONs) with aggregate induced emission enhancement (AIEE) properties have been prepared via self assembly of a cyano-substituted diarylethene derivate dye (C18-R) and synthetic copolymers, which were obtained by reversible addition-fragmentation chain transfer (RAFT) polymerization using stearyl methacrylate and poly(ethylene glycol) methacrylate as monomers. Thus obtained FONs were characterized by a series of techniques including transmission electron microscopy, Fourier transform infrared spectroscopy and fluorescent spectroscopy. To explore their potential biomedical applications, biocompatibility and cell uptake behavior of these red FONs were subsequently investigated. We demonstrated that FONs showed uniform morphology, suitable particle size (70-90 nm), high water dispersibility, strong red fluorescence and excellent biocompatibility, making them promising for bioimaging applications.

Preparation and characterization of electrospun PLGA/gelatin nanofibers as a drug delivery system by emulsion electrospinning.

Novel biocompatible poly(lactide-co-glycolide) (PLGA) nanofiber mats with favorable biocompatibility and good mechanical strength were prepared, which could serve as an innovative type of tissue engineering scaffold or an ideal controllable drug delivery system. Both hydrophobic and hydrophilic drugs, Cefradine and 5-fluorouracil were successfully loaded into PLGA nanofiber mats by emulsion electrospinning. The natural bioactive protein gelatin (GE) was incorporated into the nanofiber mats to improve the surface properties of the materials for cell adhesion. Nanofibrous scaffolds were characterized by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, contact angle and tensile measurements. Emulsion electrospun fibers with GE had perfect hydrophilic and good mechanical property. The in vitro release test showed thedrugs released from emulsion electrospun fibers, which achieved lower burst release. The cells cytotoxicity experiment indicated that emulsion electrospun fibers were less toxic and tended to promote fibroblasts cells attachment and proliferation, which implied that the electrospun fibers had promising potential application in tissue engineering or drug delivery.

Synthesis and cytotoxicity of brefeldin A conjugated monomethoxy-poly(ethylene glycol)-b-poly(L-lactide) polymeric micelles.

A diblock copolymer of monomethoxy-poly(ethylene glycol)-b-poly(L-lactide) (MePEG-PLLA)/brefeldin A (BFA) conjugate was synthesized by the reaction of carboxyl-terminated copolymer MePEG-PLLA with BFA in the presence of dicyclohexylcarbodiimide and dimethylaminopyridine. The conjugation efficiency was found to be 95%. Its structure was confirmed by (1)H nuclear magnetic resonance and gel permeation chromatography. The MePEG-PLLA/BFA conjugate could self-assemble into micelles in aqueous solutions with a low critical micelle concentration of 1.8 × 10(-3 )g/L. Dynamic light scattering and transmission electron microscopy analyses of the MePEG-PLLA/BFA micelles revealed their spherical structure with an average diameter of 120 nm. The release profiles of BFA in PBS were measured by high performance liquid chromatography (HPLC), demonstrating that the controlled release of BFA can be gained for long time. The in vitro antitumor activity of the conjugate micelles against human liver carcinoma HepG2 cells was evaluated by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyl tetrazolium bromide method, and the results showed that BFA can be released from the conjugate micelles without losing cytotoxicity.

Controlled release of brefeldin A from electrospun PEG-PLLA nanofibers and their in vitro antitumor activity against HepG2 cells.

In this work, PEG-PLLA electrospun fibers were developed as a new controlled release system for macrolide antibiotic drug brefeldin A (BFA). SEM and XRD analyses of the BFA-loaded PEG-PLLA fibers revealed that the average diameter of fibers was below 950 nm with smooth surfaces, and the drug was well incorporated into the fibers in amorphous form. The release profiles of BFA in PBS were measured by HPLC, demonstrating that the controlled release of BFA could be gained for long time. The in vitro antitumor activity against human liver carcinoma HepG2 cells of the fibers containing 3%, 6%, 9%, 12% and 15% BFA were examined by MTT method, and the results showed that cell growth inhibition rates at 72 h were 64%, 77%, 80%, 81% and 85%, respectively. These results strongly suggested that the BFA/PEG-PLLA fibers had an effect of controlled release of BFA and were suitable for postoperative chemotherapy of cancers.

Electrospinning of poly(L-lactide) nanofibers encapsulated with water-soluble fullerenes for bioimaging application.

Photoluminescent fullerene nanoparticles/nanofibers have potential applications in bioimaging. A novel fluorescent nanofibrous material, consisting of fullerene nanoparticles and poly(L-lactide) (PLLA), was fabricated via a simple electrospinning method, and the composite nanofibers were characterized by various techniques such as scanning electron microscopy (SEM), laser scanning confocal microscopy (LSCM), and transmission electron microscopy (TEM). The nanofibers were uniform, and their surfaces were reasonably smooth, with the average diameters of fibers ranging from 300 to 600 nm. The fullerene nanoparticles were encapsulated within the composite nanofibers, forming a core-shell structure. The nanofiber scaffolds showed excellent hydrophilic surface due to the addition of water-soluble fullerene nanoparticles. The composite nanofibers used as substrates for bioimaging in vitro were evaluated with human liver carcinoma HepG2 cells, the fullerene nanoparticles signal almost displayed in every cell, implying the potential of fluorescent fullerene nanoparticles/PLLA nanofibers to be used as scaffolds for bioimaging application.

(2,4-Dichloro-phen-yl)(diphenyl-phosphor-yl)methanol.

In the title compound, C(19)H(15)Cl(2)O(2)P, the dihedral angle between the mean planes of the phenyl rings bonded to the P atom is 75.4 (1)°. In the crystal, mol-ecules are linked into chains running along the a axis by inter-molecular O-H⋯O hydrogen bonds. Mol-ecules are further connected into a three-dimensional array by weak C-H⋯O inter-actions.

(Diphenyl-phosphor-yl)(2-nitro-phen-yl)methanol.

In the title compound, C(19)H(16)NO(4)P, the dihedral angle between the mean planes of the phenyl rings bonded to the P atom is 75.4 (1)°. In the crystal, mol-ecules are linked into chains running along the a axis by inter-molecular O-H⋯O hydrogen bonds. Mol-ecules are further connected into a three-dimensional array by weak C-H⋯O hydrogen bonds.

Discovery of new natural products by intact-cell mass spectrometry and LC-SPE-NMR: malbranpyrroles, novel polyketides from thermophilic fungus Malbranchea sulfurea.

Six photosensitive polyketides, malbranpyrroles A-F, were discovered from the thermophilic fungus Malbranchea sulfurea by using intact-cell desorption/ionization on silicon mass (ICD-MS) and LC-SPE-NMR. These two strategies facilitate the searching and structural determination of unstable natural products. The ICD-MS indicated that only brown hyphae of M. sulfurea can produce malbranpyrroles. The biosynthetic pathway of malbranpyrroles was evidenced by 13C isotope precursors and amino acid feeding experiments. The cytotoxicity data revealed that the conformation of the conjugated system in malbranpyrroles does not affect cytotoxic potency against cancer cell lines. In addition, the chlorine atom was shown to be the pharmacophore for cytotoxicity.

(2-Chloro-phen-yl)(diphenyl-phosphor-yl)methanol.

The title compound, C(19)H(16)ClO(2)P, was obtained by the reaction of diphenyl-phosphine oxide with 2-chloro-benzaldehyde. The mol-ecule has a tetra-hedral structure at the P atom. The dihedral angle between the phenyl rings attached to the P atom is 80.4 (1)°. The mol-ecules are linked together by inter-molecular O-H⋯O and C-H⋯O hydrogen-bonding inter-actrions. The crystal studied was an inversion twin.