Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic allograft nephropathy (CAN) remains the primary reason for late allograft loss in kidney transplantation. Platelet-derived growth factor (PDGF) is a major mitogen mediating mesenchymal cell proliferation in CAN. When administered continuously the PDGF receptor tyrosine kinase inhibitor imatinib prevents the development of CAN and restores kidney function in experimental kidney transplantation. Herein we investigated whether early short-term imatinib treatment prevented CAN. Kidney transplantations were performed from DA to WF rats and syngenic controls were done between DA rats. Allograft recipients were immunosuppressed with cyclosporine (CsA; 1.5 mg/kg/d sc). One group of allografts was also treated with imatinib (10 mg/kg/d po). Serum creatinine levels were measured once a week. Grafts were harvested 90 days after transplantation for histology and immunohistochemistry (PDGF-AA, -BB, PDGFR-alpha, -beta). Histological changes were scored according to the Chronic Allograft Damage Index (CADI). Among syngenic grafts, no signs of CAN were observed, namely, CADI 0.3 +/- 0.2 (mean +/- SEM). Control allografts showed moderate to intense chronic changes, CADI 6.5 +/- 1.3. Early short-term imatinib treatment significantly prevented the development of CAN compared with control allografts. Only a few histological changes were seen, namely, CADI 3.3 +/- 1.4. Compared with control allografts PDGF ligand and receptor induction was significantly inhibited by imatinib to nearly the same level as in syngenic grafts. Creatinine values of imatinib-treated allografts were also lower than control allografts. Our results demonstrated that early short-term imatinib treatment significantly prevented CAN. This indicated that early PDGF induction has an important role in the pathogenesis of CAN.
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PMID:Early short-term platelet-derived growth factor inhibition prevents the development of chronic allograft nephropathy in experimental rat kidney transplantation. 1717 31

The novel biodegradable poly(epsilon-caprolactone)/titanium dioxide hybrid materials were prepared via in situ sol-gel process of tetrabutyl titanate (TBT) as inorganic precursor in the presence of PCL. The relationships between morphology, microphase separation, crystalline structure, and properties were investigated by means of XPS, SEM, XRD, DSC, and in vitro degradation test. The microstructures of the bulk hybrids display two-phase microscopic separation on the nanometer scale, which domain is 20-80 nm. The surface morphology and intermolecular bonding interaction are significantly dependent on inorganic component. The relative crystalline degrees of PCL/TiO(2) hybrid nanocomposite materials were controlled by both inorganic component and hydrogen bonding special interaction. The hybrid nanocomposite materials with TiO(2) showed faster biodegradation rate than that of pure PCL itself, and the transparency corresponding to microstructure increase with increase of inorganic component content.
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PMID:Morphology and properties of organic-inorganic hybrid materials involving TiO2 and poly(epsilon-caprolactone), a biodegradable aliphatic polyester. 1738 34

Electrospun zein membranes were prepared using DMF as solvent. By changing the solution concentration, the electrospinning voltage and the distance between the spinneret and collector, nanofibrous meshes without bead defects could be obtained. In order to improve the mechanical strength of the hydrated zein meshes, core-shell-structured nanofibrous membranes with PCL as the core material and zein forming the shell were prepared by coaxial electrospinning. The core-shell structure of the composite fibers was confirmed by SEM characterization of the fibers, either extracted with chloroform to remove the inner PCL, or elongated to expose their cross-section. The composition and average diameter of the composite fibers could be modulated by the feed rate of the inner PCL solution. It was found that the core-shell fibrous membranes have similar wettability to the electrospun zein mesh. The presence of PCL in the fibers could significantly improve the mechanical properties of the zein membrane.
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PMID:Fabrication and characterization of zein-based nanofibrous scaffolds by an electrospinning method. 1742 29

A high-temperature reductive sulfuration method is demonstrated to synthesize highly ordered mesoporous metal sulfide crystallites by using mesoporous silica as hard templates. H2S gas is utilized as a sulfuration agent to in situ convert phosphotungstic acid H3PW12O40.6H2O to hexagonal WS2 crystallites in the silica nanochannels at 600 degrees C. Upon etching silica, mesoporous, layered WS2 nanocrystal arrays are produced with a yield as high as 96 wt %. XRD, nitrogen sorption, SEM, and TEM results reveal that the WS2 products replicated from the mesoporous silica SBA-15 hard template possess highly ordered hexagonal mesostructure (space group, p6mm) and rodlike morphology, analogous to the mother template. The S-W-S trilayers of the WS2 nanocrystals are partially oriented, parallel to the mesochannels of the SBA-15 template. This orientation is related with the reduction of the high-energy layer edges in layered metal dichalcogenides and the confinement in anisotropic nanochannels. The mesostructure can be 3-D cubic bicontinuous if KIT-6 (Iad) is used as a hard template. Mesoporous WS2 replicas have large surface areas (105-120 m2/g), pore volumes ( approximately 0.20 cm3/g), and narrow pore size distributions ( approximately 4.8 nm). By one-step nanocasting with the H3PMo12O40.6H2O (PMA) precursor into the mesochannels of SBA-15 or KIT-6 hard template, highly ordered mesoporous MoS2 layered crystallites with the 2-D hexagonal (p6mm) and 3-D bicontinuous cubic (Iad) structures can also be prepared via this high-temperature reductive sulfuration route. When the loading amount of PMA precursor is low, multiwalled MoS2 nanotubes with 5-7 nm in diameter can be obtained. The high-temperature reductive sulfuration method is a general strategy and can be extended to synthesize mesoporous CdS crystals and other metal sulfides.
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PMID:Synthesis of highly ordered mesoporous crystalline WS(2) and MoS(2) via a high-temperature reductive sulfuration route. 1762 61

In this article, nano-magnetite particles (ferrofluid, Fe3O4) were prepared by chemical co-deposition method. A series of biodegradable triblock poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL, PCEC) copolymers were synthesized by ring-opening polymerization method from epsilon-caprolactone (epsilon-CL) initiated by poly(ethylene glycol) diol (PEG) using stannous octoate as catalyst. And the magnetic PCEC composite microspheres were prepared by solvent diffusion method. The properties of the ferrofluid, PCEC copolymer, and magnetic PCEC microspheres were studied in detail by SEM, VSM, XRD, Malvern Laser Particle Sizer, 1H-NMR, GPC, and TG/DTG. Effects of macromolecular weight and concentration of polymer, and the time for ultrasound dispersion on properties of magnetic microspheres were also investigated. The obtained magnetic PCEC microspheres might have great potential application in targeted drug delivery system or cell separation.
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PMID:Preparation and characterization of magnetic poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) microspheres. 1770 Dec 92

The hydrolytic and Pseudomonas lipase catalysed enzymatic degradation was studied for PDC multiblock copolymers consisting of poly(epsilon-caprolactone) (PCL) segments and poly(p-dioxanone) (PPDO) segments with variable composition. The enzymatic degradation of these multiblock copolymers is significantly accelerated by Pseudomonas lipase in contrast to the hydrolytic degradation where the degradation behaviour is determined by the PPDO segments. Degradation time intervals up to 200h are selected, where the PPDO segments remain stable and do not contribute to the degradation process. A linear correlation between weight loss and increasing PCL content of the multiblock copolymers was found. X-ray diffraction data confirm that both crystalline and amorphous PCL are attacked by the enzymes. SEM cross-section images reveal that Pseudomonas lipase penetrates into the PDC polymers. The present study impressively demonstrates that selective enzymatic degradation of PCL containing multifunctional polymers is a beneficial tool for controlling their degradation properties.
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PMID:Selective enzymatic degradation of poly(epsilon-caprolactone) containing multiblock copolymers. 1788 1

Drug delivery applications using biodegradable polymeric microspheres are becoming an important means of delivering therapeutic agents. The aim of this work was to modulate the microporosity of poly(epsilon-caprolactone) (PCL) microcarriers to control protein loading capability and release profile. PCL microparticles loaded with BSA (bovine serum albumin) have been de novo synthesized with double emulsion solvent evaporation technique transferred and adapted for different polymer concentrations (1.7 and 3% w/v) and stabilizer present in the inner aqueous phase (0.05, 0.5 and 1% w/v). SEM (scanning electron microscope) and CLSM (confocal laser scanning microscope) analysis map the drug distribution in homogeneously distributed cavities inside the microspheres with dimensions that can be modulated by varying double emulsion process parameters. The inner structure of BSA-loaded microspheres is greatly affected by the surfactant concentration in the internal aqueous phase, while a slight influence of polymer concentration in the oil phase was observed. The surfactant concentration mainly determines microspheres morphology, as well as drug release kinetics, as confirmed by our in-vitro BSA release study. Moreover, the entrapped protein remained unaltered during the protein encapsulation process, retaining its bio-activity and structure, as shown through a dedicated gel chromatographic analytical method.
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PMID:Engineering of poly(epsilon-caprolactone) microcarriers to modulate protein encapsulation capability and release kinetic. 1791 22

The present study was carried out in order to examine the anticancer properties of two sesquiterpene lactones, millerenolide and thieleanin, isolated from Viguiera sylvatica and Decachaeta thieleana, against cell lines in vitro, and on the growth B16/BL6 melanoma tumors in C57BL/6 mice. Millerenolide and thieleanin showed a similar pattern of cytotoxicity with the greatest effect on viability being evident with A549 human lung cancer cells (IC(50) - 40 and 32 microM respectively), and with the 3T3/HER2 cell line which are 3T3 mouse fibroblasts transfected with the HER2 oncogene (IC(50) - 16 and 28 microM respectively). The parent 3T3 cells and the B16/BL6 mouse melanoma cells were less sensitive to these compounds, with thieleanin showing an IC(50) with B16/BL6 greater than the highest dose tested (203 microM). Treatment with millerenolide (8 mg/kg, i.p. on days 0, 2 and 4 post-inoculation) significantly inhibited the growth of subcutaneous B16/BL6 tumors in C57BL/6 mice, (50% inhibition at day 25, P=0.015), as well as retarding the appearance of detectable tumor (millerenolide - day 15.2+/-0.4 vs control - day 12.8+/-0.5, mean+/-SEM, P=0.011). In contrast, treatment with thieleanin (8 mg/kg every other day up to the day of kill) neither retarded the appearance of the tumor nor its growth.
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PMID:Anticancer activities of two sesquiterpene lactones, millerenolide and thieleanin isolated from Viguiera sylvatica and Decachaeta thieleana. 1853 79

A common method used to prepare polymeric nanoparticles in pharmaceutical technology is emulsion-diffusion. However, this method has several disadvantages due to the long duration of the process. At the diffusion step of conventional emulsion-diffusion, high pressure treatment could replace the addition of great quantities of water resulting in diffusion of the solvents from the internal phase to the external phase. The objective of the present study was to develop a novel method for nanoparticle formulation by combining high pressure treatment with the emulsion-diffusion method to avoid an additional diffusion step in the aqueous phase. After emulsification at 11,000 rpm, the emulsions were pressurized at 100, 200 and 300 Mpa, each for 300, 600, 900 or 1200 s. The mean size and morphology of the nanoparticles were analysed by Mastersizer, TEM and SEM. The mean size of pressurized emulsion nanoparticles was the same at 100 MPa for holding times up to 600 s. Also, the pressurized emulsion nanoparticle size increased and the peak and width of the size distribution curve was higher and slightly narrower depending on the pressure and the holding time. This study shows that pressure treatment can produce polymer membranes surrounding the oil surface owing to the precipitation of PCL, inducing the diffusion of solvent from the interior to the exterior based on TEM images. From these results, it is believed that high pressure treatment should be considered as a successful alternative for preparing nanoparticles.
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PMID:Development of a novel nanocapsule formulation by emulsion-diffusion combined with high hydrostatic pressure. 1860 95

We report here a detailed study on the surface topology of well-known ordered mesoporous silica (SBA-15, MCM-41, and KIT-6) and a series of nanocast Co 3O 4, Co 3O 4/CoFe 2O 4 composites by high resolution scanning electron microscopy (HR-SEM). Images of the MCM-41 structure were obtained at a resolution of the pore size, as well as a real space image of the gyroid silica surface of KIT-6 for two different aging temperatures, clearly revealing the differences of the aging procedures. By using the low voltage HR-SEM technique with extremely high resolution, we could very clearly show the influence of the template properties on the structure of the nanocast metal oxides.
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PMID:Direct imaging of surface topology and pore system of ordered mesoporous silica (MCM-41, SBA-15, and KIT-6) and nanocast metal oxides by high resolution scanning electron microscopy. 1867 51


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