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)

In this contribution, PCL (poly-epsilon caprolactone) scaffolds were prepared by solvent-casting/particle-leaching technique in the presence of two pore formers, PEG(4000) or sucrose molecules in different quantities (0, 10, 20, 30, 40, 50, 55 w/w% PEG(4000)/PCL; 10, 20 w/w% Sucrose/PCL). The surface and bulk properties of the resulting scaffolds were studied by SEM, DSC and FTIR. SEM photographs showed that, macroporosity was obtained in the PCL structures prepared with sucrose crystals while microporous structure was obtained in the presence of PEG(4000) molecules. Average pore diameters calculated from SEM photographs were 40.1 and 191.2 mum for 40% PEG(4000)/PCL and 10% Sucrose/PCL scaffolds, respectively. The DSC and FTIR results confirmed that there is no any interaction between pore formers and PCL during structural formation, and both pore formers, PEG(4000) and sucrose, remained independently in the scaffolds. L929 mouse fibroblast cells were seeded onto PCL structures and maintained during 7 days to evaluate cell proliferation. Cell culture results showed that, 10% Sucrose/PCL scaffold was the most promising substrate for L929 cell growth due to 3-D architecture and macroporous structure of the scaffold.
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PMID:Comparison of cellular proliferation on dense and porous PCL scaffolds. 1872 92

Nerve tissue engineering is one of the most promising methods to restore nerve systems in human health care. Scaffold design has pivotal role in nerve tissue engineering. Polymer blending is one of the most effective methods for providing new, desirable biocomposites for tissue-engineering applications. Random and aligned PCL/gelatin biocomposite scaffolds were fabricated by varying the ratios of PCL and gelatin concentrations. Chemical and mechanical properties of PCL/gelatin nanofibrous scaffolds were measured by FTIR, porometry, contact angle and tensile measurements, while the in vitro biodegradability of the different nanofibrous scaffolds were evaluated too. PCL/gelatin 70:30 nanofiber was found to exhibit the most balanced properties to meet all the required specifications for nerve tissue and was used for in vitro culture of nerve stem cells (C17.2 cells). MTS assay and SEM results showed that the biocomposite of PCL/gelatin 70:30 nanofibrous scaffolds enhanced the nerve differentiation and proliferation compared to PCL nanofibrous scaffolds and acted as a positive cue to support neurite outgrowth. It was found that the direction of nerve cell elongation and neurite outgrowth on aligned nanofibrous scaffolds is parallel to the direction of fibers. PCL/gelatin 70:30 nanofibrous scaffolds proved to be a promising biomaterial suitable for nerve regeneration.
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PMID:Electrospun poly(epsilon-caprolactone)/gelatin nanofibrous scaffolds for nerve tissue engineering. 1875 94

Previously, we have demonstrated that 2,2-bis(2-oxazoline) linked poly-epsilon-caprolactone (PCL-O) is degraded in vitro enzymatically by surface erosion which could enable the novel use of this material for drug delivery and other biomedical applications. In this study, degradation, erosion (weight loss) and toxicity of PCL-O poly(ester-amide)s were evaluated in vivo. PCL and three PCL-O polymers with different PCL block lengths (M(n): 1500, 3900, 7500 g/mol) were melt-pressed in the form of discs and implanted subcutaneously in Wistar rats (dose approximately 340 mg/kg) for 1, 4 and 12 weeks. With implantation for 12 weeks, up to 16.5% weight loss of polymer discs was measured for the most extensively linked PCL-O polymer (block length 1500 g/mol) whereas practically no weight loss was observed with the other polymers. NMR, DSC and SEC studies as well as SEM micrographs before and after implantation and in vitro hydrolysis studies indicate that enzyme based surface erosion of PCL-O polymers occurred in vivo. The in vivo evaluation based on results from hematology, clinical chemistry and histology of the implantation area and main organs (i.e. heart, lung, liver, kidney, spleen and brain) demonstrated that PCL-O polymers are biocompatible and safe, enzyme sensitive biomaterials.
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PMID:In vivo implantation of 2,2'-bis(oxazoline)-linked poly-epsilon-caprolactone: proof for enzyme sensitive surface erosion and biocompatibility. 1902 79

For dye-sensitized solar cell (DSSC), highly ordered nanoporous TiO2 materials with crystalline frameworks were successfully synthesized from different silica templates including SBA-15, KIT-6 and MSU-H. A photoelectrode in DSSC was fabricated by adsorbing cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)-ruthenium(II)bis-tetrabutylammonium dye (N719) onto the prepared TiO2 nanoparticles. The samples were characterized by XRD, TEM, FE-SEM, AFM and Brunauer-Emmett-Teller (BET), and FT-IR analysis. An investigation of the influence of the bonding structure of N719 dye and nanoporous TiO2 on the photovoltaic performance of DSSC revealed that the bonding structure of N719 on TiO2 films is caused by the unidentate and bidentate linkage. Based on the overall conversion efficiency (eta), fill factor (FF), open-circuit voltage (V(oc)) and short-circuit current (/sc) from the I-V curves measured, it was observed that the photoelectric performance is strongly dependent on the dispersion properties of the nanoporous TiO2 replicas from mesoporous silica templates.
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PMID:Photovoltaic performance of nanoporous TiO2 replicas synthesized from mesoporous materials for dye-sensitized solar cells. 1919 74

The purpose of this study was to develop a novel polymer cuff for the local delivery of alpha-lipoic acid (ALA) to inhibit neointimal formation in vivo. The polymer cuff was fabricated by incorporating the ALA into poly- (D,L-lactide-co-caprolactone) 40:60 (PLC), with or without methoxy polyethylene glycol (MethoxyPEG). The release kinetics of ALA and in vitro degradation by hydrolysis were analyzed by HPLC and field emission scanning electron microscopy (FE-SEM), respectively. In vivo evaluation of the effect of the ALA-containing polymer cuff was carried out using a rat femoral artery cuff injury model. At 24 h, 48% or 87% of the ALA was released from PCL cuffs with or without MethoxyPEG. FE-SEM results indicated that ALA was blended homogenously in the PLC with MethoxyPEG, whereas ALA was distributed on the surface of the PLC cuff without MethoxyPEG. The PLC cuff with MethoxyPEG showed prolonged and controlled release of ALA in PBS, in contrast to the PLC cuff without MethoxyPEG. Both ALA-containing polymer cuffs had a significant effect on the inhibition of neointimal formation in rat femoral artery. Novel ALA-containing polymer cuffs made of PLC were found to be biocompatible and effective in inhibiting neointimal formation in vivo. Polymer cuffs containing MethoxyPEG allowed the release of ALA for one additional week, and the rate of drug release from the PLC could be controlled by changing the composition of the polymer. These findings demonstrate that polymer cuffs may be an easy tool for the evaluation of anti-restenotic agents in animal models.
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PMID:Fabrication of an alpha-lipoic acid-eluting poly-(D,L-lactide-co-caprolactone) cuff for the inhibition of neointimal formation. 1928 97

Nanofibrous scaffolds have morphological similarities to native extracellular matrix and have been considered as candidate scaffolds in tissue engineering. However, there is no report on the effect of the thickness of nanofibrous scaffold on cell behavior. In this study poly (epsilon-caprolactone) (PCL) nanofibrous scaffolds with thicknesses of 0.1 and 0.6 mm were fabricated by electrospinning. Properties of PCL nanofibrous scaffolds were measured by contact angle and air permeability measurements while the morphology of the nanofibers was observed by SEM. Mouse embryonal carcinoma stem cells (P19), monkey epithelial kidney cells (Vero), Chinese hamster ovary cells (CHO) and mouse mesenchymal stem cells (MSCs) were seeded on PCL nanofibrous scaffolds with thicknesses of 0.1 and 0.6 mm. Air permeability measurements showed that air permeability decreases with the increase in the thickness of nanofibrous scaffolds, and contact angle measurements revealed a contact angle of 118 degrees for electrospun PCL nanofibers. The MTT assays showed that the proliferation of the cells was influenced by the thickness of the nanofibrous scaffold. Scaffolds with a thickness of 0.6 mm were found to provide a better substrate for cell proliferation, possibly due to more dimensional stability. Therefore, regardless of cell origin, thicker scaffolds provide a better substrate for cell proliferation, possibly due to the higher dimensional stability and tightness of thicker scaffolds.
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PMID:The thickness of electrospun poly (epsilon-caprolactone) nanofibrous scaffolds influences cell proliferation. 1944 Sep 90

Poly(epsilon-caprolactone) (PCL) implants containing praziquantel (PZQ), a broad-spectrum antiparasite drug, are fabricated by injection molding and characterized in terms of content uniformity, morphology, drug physical state and stability. In vitro drug release from the implants is also studied. It is found that drug is dispersed uniformly in all implants and keeps stable over 365 days at 4 degrees C/60% RH. X-ray diffraction analysis reveals that PZQ exists primarily in its crystalline state in implants with high drug contents (50% and 25%). All implants exhibit similar release behaviors and about 70% of the drug is released after 365 days. The cross-sections of all implants present two distinct zones (i.e. peripheral white zone and inner pink zone) and the boundary between the two zones changes as time progresses. Drug content in the white zone is very low (less than 1%), but drug content in the pink zone is almost the same as the predefined value. Porous structures in the white zone but dense structures in the pink zone are observed by SEM. Obvious PCL degradation occurs till up to 365 days. These results show that the release process of PZQ is a gradual diffusion from the exterior to the interior of the implants.
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PMID:Characterization and in vitro release of praziquantel from poly(epsilon-caprolactone) implants. 1944 18

The aim of current study is to investigate the in vitro and in vivo behavior of dental pulp stem cells (DPSCs) seeded on electrospun poly(epsilon-caprolactone) (PCL)/gelatin scaffolds with or without the addition of nano-hydroxyapatite (nHA). For the in vitro evaluation, DNA content, alkaline phosphatase (ALP) activity and osteocalcin (OC) measurement showed that the scaffolds supported DPSC adhesion, proliferation, and odontoblastic differentiation. Moreover, the presence of nHA upregulated ALP activity and promoted OC expression. Real-time PCR data confirmed these results. SEM micrographs qualitatively confirmed the proliferation and mineralization characteristics of DPSCs on both scaffolds. Subsequently, both scaffolds seeded with DPSCs were subcutaneously implanted into immunocompromised nude mice. Scaffolds with nHA but without cells were implanted as control. Histological evaluation revealed that all implants were surrounded by a thin fibrous tissue capsule without any adverse effects. The cell/scaffold composites showed obvious in vivo hard tissue formation, but there was no sign of tissue ingrowth. Further, the combination of nHA in scaffolds did upregulate the expression of specific odontogenic genes. In conclusion, the incorporation of nHA in nanofibers indeed enhanced DPSCs differentiation towards an odontoblast-like phenotype in vitro and in vivo.
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PMID:The performance of dental pulp stem cells on nanofibrous PCL/gelatin/nHA scaffolds. 1955 87

In the present study, porous PCL (poly (epsilon-caprolactone)) scaffolds were prepared through a melted extrusion manufacturing (MEM) machine, and carboxylate groups were formed on the surfaces of specimen by hydrolyzation with NaOH aqueous solutions. Apatite precursor was introduced on the surfaces of specimens with CaCl2 and K2 HPO4 under vacuum condition, and mineralization study was applied to these specimens. The results showed that the hydrophilicity of PCL surface was improved with the introduction of carboxylate groups, and the contact angle of surface was decreased to 26.52 degrees. A dense and uniform bone-like layer was confirmed to be formed on the surface of Ca-P treated specimens after mineralizing for less than 24 h in SBF by SEM and EDAX.
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PMID:[Preparation of novel bioactive PCL bone tissue engineering scaffold]. 1963 71

Neuronal apoptosis occurs in the diabetic brain due to insulin deficiency or insulin resistance, both of which reduce the expression of stem cell factor (SCF). We investigated the possible involvement of the activation of the MAPK/ERK and/or AKT pathways in neuroprotection by SCF in diabetes. Male C57/B6 mice (20-25 g) were randomly divided into four groups of 10 animals each. The morphology of the diabetic brain in mice treated or not with insulin or SCF was evaluated by H&E staining and TUNEL. SCF, ERK1/2 and AKT were measured by Western blotting. In diabetic mice treated with insulin or SCF, there was fewer structural change and apoptosis in the cortex compared to untreated mice. The apoptosis rate of the normal group, the diabetic group receiving vehicle, the diabetic group treated with insulin, and the diabetic group treated with SCF was 0.54 +/- 0.077%, 2.83 +/- 0.156%, 1.86 +/- 0.094%, and 1.78 +/- 0.095% (mean +/- SEM), respectively. SCF expression was lower in the diabetic cortex than in the normal cortex; however, insulin increased the expression of SCF in the diabetic cortex. Furthermore, expression of phosphorylated ERK1/2 and AKT was decreased in the diabetic cortex compared to the normal cortex. However, insulin or SCF could activate the phosphorylation of ERK1/2 and AKT in the diabetic cortex. The results suggest that SCF may protect the brain from apoptosis in diabetes and that the mechanism of this protection may, at least in part, involve activation of the ERK1/2 and AKT pathways. These results provide insight into the mechanisms by which SCF and insulin exert their neuroprotective effects in the diabetic brain.
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PMID:Stem cell factor protects against neuronal apoptosis by activating AKT/ERK in diabetic mice. 1980 67


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