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Ji Young Yoon, Keum-Jin Yang, Shi-Nae Park, Dong-Kee Kim, Jong-Duk Kim
Dexamethasone (Dex)-loaded PHEA-g-C18-Arg8 (PCA) nanoparticles (PCA/Dex) were developed for the delivery of genes to determine the synergistic effect of Dex on gene expression. The cationic PCA nanoparticles were self-assembled to create cationic micelles containing an octadecylamine (C18) core with Dex and an arginine 8 (Arg8) peptide shell for electrostatic complexation with nucleic acids (connexin 26 [Cx26] siRNA, green fluorescent protein [GFP] DNA or brain-derived neurotrophic factor [BDNF] pDNA). The PCA/Dex nanoparticles conjugated with Arg8, a cell-penetrating peptide that enhances permeability through a round window membrane in the inner ear for gene delivery, exhibited high uptake efficiency in HEI-OC1 cells...
2016: International Journal of Nanomedicine
Wei Chen, Yong Hou, Zhaoxu Tu, Lingyan Gao, Rainer Haag
pH-Degradable PVA nanogels, which are prepared by photo-crosslinking thermo-preinduced PVA nanoaggregates in water without any surfactants or toxic organic solvents, are used for intracellular PTX release and anticancer treatment. These nanogels fast degraded at mildly acidic conditions with a pH-triggered PTX release, and the degradation products are only native PVA and poly(hydroxyethyl acrylate) (PHEA) as well as acetaldehyde without any toxic byproducts. The nanogel sizes could be tailored by different temperatures during the crosslinking process...
October 31, 2016: Journal of Controlled Release: Official Journal of the Controlled Release Society
José M Camacho-Zaragoza, Georgina Hernández-Chávez, Fabian Moreno-Avitia, René Ramírez-Iñiguez, Alfredo Martínez, Francisco Bolívar, Guillermo Gosset
BACKGROUND: Resveratrol is a plant natural product with many health-protecting effects which makes it an attractive chemical both for academic studies and industrial purposes. However, the low quantities naturally produced by plants as well as the unsustainable procedures of extraction, purification and concentration have prompted many biotechnological approaches to produce this chemical in large quantities from renewable sources. None of these approaches have considered a microbial coculture strategy to produce this compound...
September 29, 2016: Microbial Cell Factories
Dongqin Ding, Yongfei Liu, Yiran Xu, Ping Zheng, Haixing Li, Dawei Zhang, Jibin Sun
L-Phenylalanine (L-Phe) is an important amino acid used in both food and medicinal applications. We developed an in vitro system that allowed a direct, quantitative investigation of phenylalanine biosynthesis in E. coli. Here, the absolute concentrations of six enzymes (AroK, AroL, AroA, AroC, PheA and TyrB) involved in the shikimate (SHIK) pathway were determined by a quantitative proteomics approach and in vitro enzyme titration experiments. The reconstitution of an in vitro reaction system for these six enzymes was established and their effects on the phenylalanine production were tested...
2016: Scientific Reports
J H Chun, J M Cheon, B Y Jeong, N J Jo
We synthesized the urethane/siloxane acrylate oligomer from isophorone diisocyanate (IPDI), hydroxyl alkyl terminated polydimethylsiloxane and 2-hydroxyethyl acrylate (2-HEA). UV-curable resins were formulated from the synthesized oligomer, ethylene glycol phenyl ether acrylate (PHEA), 1,6-hexanediol diacrylate (HDDA), trimethylolpropane triacrylate (TMPTA) as a reactive diluent, 3-isocyanato-1-propene as an adhesion promoter and photoinitiators. The PET film was treated with plasma in order to introduce the functional group on the PET surface and the functional group was observed through X-ray photoelectron spectroscopy (XPS) and the Fourier transform infrared (FT-IR)...
March 2016: Journal of Nanoscience and Nanotechnology
Carlos Molina-Santiago, Baldo F Cordero, Abdelali Daddaoua, Zulema Udaondo, Javier Manzano, Miguel Valdivia, Ana Segura, Juan-Luis Ramos, Estrella Duque
Aromatic compounds such as L-phenylalanine, 2-phenylethanol and trans-cinnamate are aromatic compounds of industrial interest. Current trends support replacement of chemical synthesis of these compounds by 'green' alternatives produced in microbial cell factories. The solvent tolerant Pseudomonas putida DOT-T1E strain was genetically modified to produce up to 1 g l-1 of L-phenylalanine. In order to engineer this strain, the following stepwise process was carried out: 1) we selected random mutants that are resistant to toxic phenylalanine analogs; 2) we then deleted up to five genes belonging to phenylalanine metabolism pathways, which greatly diminished the internal metabolism of phenylalanine; 3) in these mutants, we overexpressed the pheAfbr gene, which encodes a recombinant variant of PheA that is insensitive to feed-back inhibition by phenylalanine...
July 14, 2016: Microbiology
E F Craparo, S Di Gioia, A Trapani, S Cellamare, G Belgiovine, D Mandracchia, G Giammona, G Cavallaro, M Conese
In this study, novel polymeric nanoparticles (NPs) were developed and their potential as carriers for beclomethasone dipropionate (BDP) into the lung after aerosolization was demonstrated by in vivo studies in mice. In particular, these NPs were obtained starting from two polyaspartamide-based copolymers which were synthesized by chemical reaction of α,β-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) and its pegylated derivative (PHEA-PEG2000) with poly(lactic acid) (PLA). To obtain nanosized particles, the high pressure homogenization (HPH)-solvent evaporation method was followed by using an organic phase containing both PHEA-PLA and PHEA-PEG2000-PLA (at a weight ratio equal to 1:1), lactose as cryoprotectant and no surfactant was adopted...
August 20, 2016: International Journal of Pharmaceutics
Maria José Valera, Albert Mas, Wolfgang R Streit, Estibaliz Mateo
BACKGROUND: We report on the functional screening and identification of an active quorum quenching (QQ) gene in the Komagataeibacter europaeus strain CECT 8546, which is a member of the acetic acid bacteria (AAB). RESULTS: Using a previously published screening protocol (Schipper et al., in Appl Environ Microbiol 75:224-233, 2009. doi: 10.1128/AEM.01389-08 ) for QQ genes, we identified a single gene, designated gqqA, that interfered strongly with bacterial quorum sensing (QS) in various reporter strains...
2016: Microbial Cell Factories
Panoraia I Siafaka, Asimina P Zisi, Maria K Exindari, Ioannis D Karantas, Dimitrios N Bikiaris
Absorbable and non-absorbable dressings have been fabricated into sponges via a modified thermally induced phase separation method, using a grafted derivative of chitosan with 2-hydroxyethylacrylate (CS-g-PHEA). The material was synthesized via free-radical polymerization and was characterized with FT-IR and (1)H NMR spectroscopies. The swelling ability, biocompatibility and biodegradability of the dressings were evaluated through in vitro assays while antibacterial studies were performed using three different bacterial strains, Methicillin susceptible Staphylococcus aureus (MSSA), Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa...
June 5, 2016: Carbohydrate Polymers
Suzanne M Kosina, Megan A Danielewicz, Mujahid Mohammed, Jayashree Ray, Yumi Suh, Suzan Yilmaz, Anup K Singh, Adam P Arkin, Adam M Deutschbauer, Trent R Northen
Synthetic microbial ecology has the potential to enhance the productivity and resiliency of biotechnology processes compared to approaches using single isolates. Engineering microbial consortia is challenging; however, one approach that has attracted significant attention is the creation of synthetic obligate mutualism using auxotrophic mutants that depend on each other for exchange or cross-feeding of metabolites. Here, we describe the integration of mutant library fitness profiling with mass spectrometry based exometabolomics as a method for constructing synthetic mutualism based on cross-feeding...
July 15, 2016: ACS Synthetic Biology
Tammy J Bullwinkle, Michael Ibba
Gene expression relies on quality control for accurate transmission of genetic information. One mechanism that prevents amino acid misincorporation errors during translation is editing of misacylated tRNAs by aminoacyl-tRNA synthetases. In the absence of editing, growth is limited upon exposure to excess noncognate amino acid substrates and other stresses, but whether these physiological effects result solely from mistranslation remains unclear. To explore if translation quality control influences cellular processes other than protein synthesis, an Escherichia coli strain defective in Tyr-tRNA(Phe) editing was used...
February 23, 2016: Proceedings of the National Academy of Sciences of the United States of America
Jannis Kuepper, Jasmin Dickler, Michael Biggel, Swantje Behnken, Gernot Jäger, Nick Wierckx, Lars M Blank
The Pseudomonas putida KT2440 strain was engineered in order to produce anthranilate (oAB, ortho-aminobenzoate), a precursor of the aromatic amino acid tryptophan, from glucose as sole carbon source. To enable the production of the metabolic intermediate oAB, the trpDC operon encoding an anthranilate phosphoribosyltransferase (TrpD) and an indole-3-glycerol phosphate synthase (TrpC), were deleted. In addition, the chorismate mutase (pheA) responsible for the conversion of chorismate over prephenate to phenylpyruvate was deleted in the background of the deletion of trpDC to circumvent a potential drain of precursor...
2015: Frontiers in Microbiology
Gennara Cavallaro, Emanuela Fabiola Craparo, Carla Sardo, Gaetano Lamberti, Anna Angela Barba, Annalisa Dalmoro
Nanocarriers of amphiphilic polymeric materials represent versatile delivery systems for poorly water soluble drugs. In this work the technique of solvent evaporation from multiple emulsions was applied to produce nanovectors based on new amphiphilic copolymer, the α,β-poly(N-2-hydroxyethyl)-DL-aspartamide-polylactic acid (PHEA-PLA), purposely synthesized to be used in the controlled release of active molecules poorly soluble in water. To this aim an amphiphilic derivative of PHEA, a hydrophilic polymer, was synthesized by derivatization of the polymeric backbone with hydrophobic grafts of polylactic acid (PLA)...
November 30, 2015: International Journal of Pharmaceutics
Oswaldo Hernandez-Hernandez, Jesus Eduardo Quintanilla-Lopez, Rosa Lebron-Aguilar, Maria Luz Sanz, F Javier Moreno
This work explores the use of both hydrophilic interaction liquid chromatography (HILIC) and reverse phase liquid chromatography (RPLC) for the separation and subsequent characterization of bovine caseinomacropeptide (CMP) phosphopeptides and O-glycopeptides using a quadrupole-time-of-flight (QTOF) mass spectrometer with electrospray ionization. Two neutral, ethylene bridged hybrid (BEH) amide and polyhydroxyethyl aspartamide (PHEA), and a zwitterionic, sulfobetaine (ZIC), stationary phases were used for the HILIC mode, whilst an octadecylsilane (C18) stationary phase was employed for the RPLC separation...
January 8, 2016: Journal of Chromatography. A
Sante Di Gioia, Carla Sardo, Giuliana Belgiovine, Daniela Triolo, Maria d'Apolito, Stefano Castellani, Annalucia Carbone, Ida Giardino, Gaetano Giammona, Gennara Cavallaro, Massimo Conese
High-mobility group box 1 (HMGB1) is a nonhistone protein secreted by airway epithelial cells in hyperinflammatory diseases such as asthma. In order to down-regulate HMGB1 expression in airway epithelial cells, siRNA directed against HMGB1 was delivered through nanocomplexes based on a cationic copolymer of poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) by using H441 cells. Two copolymers were used in these experiments bearing respectively spermine side chains (PHEA-Spm) and both spermine and PEG2000 chains (PHEA-PEG-Spm)...
August 1, 2015: International Journal of Pharmaceutics
Youyong Yuan, Ryan T K Kwok, Ben Zhong Tang, Bin Liu
Integrated diagnosis and therapy systems that can offer traceable cancer therapy are in high demand for personalized medicine. Herein, a pH-responsive polymeric probe containing tetraphenylsilole (TPS) with aggregation-induced emission characteristics and pheophorbide A (PheA) photosensitizer (PS) with aggregation-caused quenching property for tracing the whole process of cancer therapy is reported. At physiological conditions (pH 7.4), the probe self-assembles into nanoparticles (NPs), which show weak fluorescence of PheA with low phototoxicity, but strong green fluorescence from TPS for probe self-tracking...
September 2015: Small
Rodrigo Sierpe, Erika Lang, Paul Jara, Ariel R Guerrero, Boris Chornik, Marcelo J Kogan, Nicolás Yutronic
We report the synthesis of a 1:1 β-cyclodextrin-phenylethylamine (βCD-PhEA) inclusion complex (IC) and the adhesion of gold nanoparticles (AuNPs) onto microcrystals of this complex, which forms a ternary system. The formation of the IC was confirmed by powder X-ray diffraction and NMR analyses ((1)H and ROESY). The stability constant of the IC (760 M(-1)) was determined using the phase solubility method. The adhesion of AuNPs was obtained using the magnetron sputtering technique, and the presence of AuNPs was confirmed using UV-vis spectroscopy (surface plasmon resonance effect), which showed an absorbance at 533 nm...
July 22, 2015: ACS Applied Materials & Interfaces
Emanuela Fabiola Craparo, Barbara Porsio, Nicolò Mauro, Gaetano Giammona, Gennara Cavallaro
Here, the synthesis and the characterization of novel amphiphilic graft copolymers with tunable properties, useful in obtaining polymeric fluorescent nanoparticles for application in imaging, are described. These copolymers are obtained by chemical conjugation of rhodamine B (RhB) moieties, polylactic acid (PLA), and O-(2-aminoethyl)-O'-methyl poly(ethylene glycol) (PEG) on α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA). In particular, PHEA is first functionalized with RhB to obtain PHEA-RhB with a derivatization degree in RhB (DDRhB ) equal to 0...
August 2015: Macromolecular Rapid Communications
David R Johnson, Fang Tian, Maxine J Roman, Eric A Decker, Julie M Goddard
Foods such as bulk oils, salad dressings, and nutritionally fortified beverages that are susceptible to oxidative degradation are often packaged in poly(ethylene terephthalate) (PET) bottles with metal chelators added to the food to maintain product quality. In the present work, a metal-chelating active packaging material is designed and characterized, in which poly(hydroxamic acid) (PHA) metal-chelating moieties were grafted from the surface of PET. Biomimetic PHA groups were grafted in a two-step UV-initiated process without the use of a photoinitiator...
May 27, 2015: Journal of Agricultural and Food Chemistry
Fuwang Chen, Jie Jiang, Hongsheng OuYang, Teng Ma, Zhiyuan Peng, Yunzhi Ma, Xinrong Chen, Daxing Pang, Songyi Lin, Linzhu Ren
Red homologous recombination has been extensively used in recombineering. Because foreign sequences, such as antibiotic resistance genes, FRT-sites, or loxP-sites, are often unwanted in mutant Escherichia coli, we established a markerless deletion system containing short homologous sequences, a positive-selectable marker (kan), and a negative-selectable marker (sacB) for E. coli. For markerless deletion of a specific region of the E. coli genome, a two-step recombination procedure using two different PCR fragments, which were amplified from pUC57-kan-sacB and pUC57-298, was performed...
July 2015: Applied Biochemistry and Biotechnology
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