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Wyniki wyszukiwania dla: CONJUGATE DRUG-NANOPARTICLES
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Electrophoretic deposition (EPD) of nanohydroxyapatite - nanosilver coatings on Ti13Zr13Nb alloy
PublikacjaTitanium and its alloys are the biomaterials most frequently used in medical engineering, especially as parts of orthopedic and dental implants. The surfaces of titanium and its alloys are usually modified to improve their biocompatibility and bioactivity, for example, in connection with the deposition of hydroxyapatite coatings. The objective of the present research was to elaborate the technology of electrophoretic deposition...
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Evolution of the nanostructure of Pt and Pt–Co polymer electrolyte membrane fuel cell electrocatalysts at successive degradation stages probed by X-ray photoemission
PublikacjaWe present a set of XPS (X-ray photoemission spectroscopy) measurements and detailed data-analysis of electrodes for polymer electrolyte membrane fuel cell (PEMFC) based on carbon supported catalysts (Pt and Pt–Co) subjected to a step-like potential cycling (accelerated degradation test). The results of the measurements complete and corroborate parallel TEM (transmission electron microscopy), XRD (X-ray diffraction) and XAS (X-ray...
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Curing behavior of epoxy/Fe 3 O 4 nanocomposites: A comparison between the effects of bare Fe 3 O 4 , Fe 3 O 4 /SiO 2 /chitosan and Fe 3 O 4 /SiO 2 /chitosan/imide/phenylalanine-modified nanofillers
PublikacjaIn this study, Fe3O4 magnetic nanoparticles (MNPs) were synthesized (B-MNP) and then modified with SiO2 to form Fe3O4/SiO2 core/shell MNPs. The Fe3O4/SiO2 MNPs were chemically functionalized with chitosan so as to gain Fe3O4/SiO2/Chitosan (CH-MNP). The CH-MNP was functionalized with a macromolecule containing imide and phenylalanine precursors to gain Fe3O4/SiO2/Chitosan/imide/phenylalanine based MNPs (CH-IM-MNP). The differences...
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Structural and luminescent study of TeO2-BaO-Bi2O3-Ag glass system doped with Eu3+ and Dy3+ for possible color-tunable phosphor application
PublikacjaTellurite glass systems of 73TeO2-4BaO-3Bi2O3-1Ag:xEu2O3-(2-x)Dy2O3 (where x = 0.5, 1, 1.5, 2 in molar ratio) composition have been successfully synthesized. In order to acquire Ag nanoparticles, materials have been heat treated at 350 °C in the air atmosphere. Structural properties of obtained samples were evaluated with various techniques. X-Ray Diffraction (XRD) measurements indicated that obtained materials are amorphous in...
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Natural Deep Eutectic Solvents as Agents for Improving Solubility, Stability and Delivery of Curcumin
PublikacjaPurpose Study on curcumin dissolved in natural deep eutectic solvents (NADES) was aimed at exploiting their beneficial properties as drug carriers. Methods The concentration of dissolved curcumin in NADES was measured. Simulated gastrointestinal fluids were used to determine the concentration of curcumin and quantum chemistry computations were performed for clarifying the origin of curcumin solubility enhancement in NADES. Results NADES...
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Foliate-Targeting Quantum Dots-β-Cyclodextrin Nanocarrier for Efficient Delivery of Unsymmetrical Bisacridines to Lung and Prostate Cancer Cells
PublikacjaTargeted drug delivery by nanocarriers molecules can increase the efficiency of cancer treatment. One of the targeting ligands is folic acid (FA), which has a high affinity for the folic acid receptors, which are overexpressed in many cancers. Herein, we describe the preparation of the nanoconjugates containing quantum dots (QDs) and β-cyclodextrin (β-CD) with foliate-targeting properties for the delivery of anticancer compound...
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Molecular mechanism of proton-coupled ligand translocation by the bacterial efflux pump EmrE
PublikacjaThe current surge in bacterial multi-drug resistance (MDR) is one of the largest challenges to public health, threatening to render ineffective many therapies we rely on for treatment of serious infections. Understanding different factors that contribute to MDR is hence crucial from the global “one health” perspective. In this contribution, we focus on the prototypical broad-selectivity proton-coupled antiporter EmrE, one of the...
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CYP3A4-dependent cellular response does not relate to CYP3A4-catalysed metabolites of C-1748 and C-1305 acridine antitumor agents in HepG2 cells
PublikacjaHigh CYP3A4 expression sensitizes tumor cells to certain antitumor agents while for others it can lower their therapeutic ef fi cacy. We have elucidated the in fl uence of CYP3A4 overexpression on the cellular response induced by antitumor acridine derivatives, C-1305 and C-1748, in two hepatocellular carcinoma (HepG2) cell lines, Hep3A4 stably transfected with CYP3A4 isoenzyme, and HepC34 expressing empty vector. The compounds...
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Imidazoacridinone-dependent lysosomal photodestruction: a pharmacological Trojan horse approach to eradicate multidrug-resistant cancers
PublikacjaMultidrug resistance (MDR) remains a primary hindrance to curative cancer therapy. Thus, introduction of novel strategies to overcome MDR is of paramount therapeutic significance. Sequestration of chemotherapeutics in lysosomes is an established mechanism of drug resistance. Here, we show that MDR cells display a marked increase in lysosome number. We further demonstrate that imidazoacridinones (IAs), which are cytotoxic fluorochromes,...
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Evaluation of possibilities in identification and susceptibility testing for Candida glabrata clinical isolates with the Integral System Yeast Plus (ISYP)
PublikacjaThe aim of this study was to evaluate possibilities of correct identification and susceptibility testing of C. glabrata clinical isolates with Integral System Yeast Plus (ISYP). For species identification, as the reference method, API Candida test and species-specific PCR reactions were used. The potential of antifungal susceptibility testing by the ISYP test was compared with the Sensititre Yeast One. Whilst the reference methods...
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The Substantial Improvement of Amphotericin B Selective Toxicity Upon Modification of Mycosamine with Bulky Substituents
PublikacjaAbstract: Background: It is assumed that the unfavorable selective toxicity of an antifungal drug Amphotericin B (AmB) can be improved upon chemical modification of the antibiotic molecule. Objective: The aim of this study was verification of the hypothesis that introduction of bulky substituents at the amino sugar moiety of the antibiotic may result in diminishment of mammalian vitro toxicity of thus prepared AmB derivatives. Methods:...
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Antifungal Activity of Capridine β as a Consequence of Its Biotransformation into Metabolite Affecting Yeast Topoisomerase II Activity
PublikacjaIn the last few years,increasing importance is attached to problems caused by fungal pathogens. Current methods of preventing fungal infections remain unsatisfactory. There are several antifungal compounds whichare highly effective in some cases, however, they have limitations in usage: Nephrotoxicity and other adverse effects. In addition, the frequent use of available fungistatic drugs promotes drug resistance....
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Organic solvents aggregating and shaping structural folding of protein, a case study of the protease enzyme
PublikacjaLow solubility of reactants or products in aqueous solutions can result in the enzymatic catalytic reactions that can occur in non-aqueous solutions. In current study we investigated aqueous solutions containing different organic solvents / deep eutectic solvents (DESs) that can influence the protease enzyme's activity, structural, and thermal stabilities. Retroviral aspartic protease enzyme is responsible for the cleavage of the...
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Electrochemical simulation of enzymatic transformations studied for the selected antitumor acridine derivatives
PublikacjaThe elucidation of the metabolic pathways and the biotransformation mechanisms of potential drugs is a crucial point in drug development. It allows to know the activation routes of the new biologically active compounds, especially in respect to their possible toxicity. Generally, in vivo or in vitro experiments with liver microsomes or hepatocytes are performed. However, these testing schemes are tedious, time consuming and of...
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Effects of Addictive Substances During Pregnancy and Infancy and Their Analysis in Biological Materials
PublikacjaThe use of addictive substances during pregnancy is a serious social problem, not only because of effects on the health of the woman and child, but also because drug or alcohol dependency it detracts from childcare and enhances the prospect of child neglect and family breakdown. Developing additive substance abuse treatment programs for pregnant women is socially important and can help ensure the health of babies, prevent subsequent...
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Tailoring the electrochemical degradation of iron protected with polypyrrole films for biodegradable cardiovascular stents
PublikacjaThe degradation of polypyrrole (PPy) coated iron is studied in phosphate buffer saline solution at 37 °C by odd random phase multisine electrochemical impedance spectroscopy (ORP-EIS). PPy is electropolymerized with anti-inflammatory salicylates incorporated in the film, as a drug release system. The modelling of EIS over time provides the quantitative description of the corrosion behaviour of the material. Thus, the reliable...
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Properties of chitosan/CuNPs coatings electrophoretically deposited on TiO2 nanotubular oxide layer of Ti13Zr13Nb alloy
PublikacjaCoatings based on chitosan/CuNPs (chit/CuNPs) were obtained by a one-step electrophoretic deposition (EPD) on nanotubular oxide layer of Ti13Zr13Nb alloy. The deposition was carried out for 1 min applying voltages of 10 and 20 V with and without the addition of dispersing agent (Polysorbate 20) to the suspension. The coatings obtained for the lower voltage were more uniform than for the higher voltage. By adding a dispersing agent,...
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Insightful Analysis of Phenomena Arising at the Metal|Polymer Interphase of Au-Ti Based Non-Enzymatic Glucose Sensitive Electrodes Covered by Nafion
PublikacjaThis paper focuses on the examination of glucose oxidation processes at an electrode material composed of gold nanoparticles embedded in a titanium template. Three dierent conditions were investigated: the chloride content in the electrolyte, its ionic conductivity and the presence of a Nafion coating. The impact of the provided environment on the oxidation reaction was evaluated by cyclic voltammetry (CV) and electrochemical impedance...
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Cu-HKUST-1 and Hydroxyapatite–The Interface of Two Worlds toward the Design of Functional Materials Dedicated to Bone Tissue Regeneration
PublikacjaA novel composite based on biocompatible hydroxyapatite (HA) nanoparticles and Cu-HKUST-1 (Cu-HKUST-1@HA) has been prepared following a layer-by-layer strategy. Cu-HKUST-1 was carefully selected from a group of four Cu-based metal−organic frameworks as the material with the most promising antimicrobial activity. The formation of a colloidal Cu- HKUST-1 layer on HA nanoparticles was confirmed by various techniques, e.g., infrared...
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Fabrication of the cross-linked PVA/TiO2/C nanocomposite membrane for alkaline direct methanol fuel cells
PublikacjaA crosslinked Poly(vinyl alcohol) based composite membrane was developed through a phase inversion process for use in alkaline direct methanol fuel cells (ADMFCs). The titanium dioxide (TiO2) and carbon nanoparticles (NPs) have been incorporated into the PVA polymer matrix to improve the mechanical and thermal properties. The membrane samples were further modified with maleic acid, a carboxylic acid acting as the cross-linker,...
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Significant Production of Thermal Energy in Partially Ionized Hyperbolic Tangent Material Based on Ternary Hybrid Nanomaterials
PublikacjaNanoparticles are frequently used to enhance the thermal performance of numerous materials. This study has many practical applications for activities that have to minimize losses of energy due to several impacts. This study investigates the inclusion of ternary hybrid nanoparticles in a partially ionized hyperbolic tangent liquid passed over a stretched melting surface. The fluid motion equation is presented by considering the...
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Mechanism of Reduced Sintering Temperature of Al2O3–ZrO2 Nanocomposites Obtained by Microwave Hydrothermal Synthesis
PublikacjaA novel method to obtain Al2O3–ZrO2 nanocomposites is presented. It consists of the co-precipitation step of boehmite (AlO(OH)) and ZrO2, followed by microwave hydrothermal treatment at 270 ◦ C and 60 MPa, and by calcination at 600 ◦ C. Using this method, we obtained two nanocomposites: Al2O3–20 wt % ZrO2 and Al2O3–40 wt % ZrO2. Nanocomposites were characterized by Fourier transformed infrared spectroscopy, Raman spectroscopy,...
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Biological and mechanical properties of bone cement with nanoarticles - in vitro and in vivo research
PublikacjaDespite antibiotic preventive treatment both before and after implant implementation, the risks of infection are real. These infections develop at the implant surface a few months after inserting them into the body. To prevent the development of bacteria and reduce the risk of infection, implants coated with nanoparticles are used. The Mechanical Department of the Technical University of Gdansk carries out research into using bone...
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Solubility advantage of sulfanilamide and sulfacetamide in natural deep eutectic systems: experimental and theoretical investigations
PublikacjaObjective: The aim of this study was to explore the possibility of using natural deep eutectic solvents (NADES) as solvation media for enhancement of solubility of sulfonamides, as well as gaining some thermodynamic characteristics of the analyzed systems. Significance: Low solubility of many active pharmaceutical ingredients is a well-recognized difficulty in pharmaceutical industry, hence the need for different strategies addressing...
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Conformational Preferences of Proline Derivatives Incorporated into Vasopressin Analogues: NMR and Molecular Modelling Studies
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Highly Potent Antidiuretic Antagonists: Conformational Studies of Vasopressin Analogues Modified with 1-Naphthylalanine Enantiomers at Position 2
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Effects of an immunosuppressive treatment on the rat prostate
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Structure–activity relationships study on biological activity of peptides as dipeptidyl peptidase IV inhibitors by chemometric modeling
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Design and characteristics of gellan gum beads for modified release of meloxicam
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Aryl- and heteroaryl-substituted phenylalanines as AMPA receptor ligands
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Short Term Monitor of Photodegradation Processes in Ranitidine Hydrochloride Observed by FTIR and ATR FTIR
PublikacjaThe effects of degradation of ranitidine hydrochloride exposed to UVB radiation (l = 310 nm) and oxygen in a weathering chamber were studied by Fourier Transform Infrared spectroscopy (FTIR) and Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR). ATR-FTIR profile indicated that the degradation was spatially heterogeneous. Significant amounts of photoproducts were detected only in a directly...
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CDK9: Therapeutic Perspective in HCC Therapy
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Current Challenges in Targeting Tumor Desmoplasia to Improve the Efficacy of Immunotherapy
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Investigating the disease‐modifying properties of sclerotiorin in Alzheimer's therapy using acetylcholinesterase inhibition
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Current state of a dual behaviour of antimicrobial peptides-Therapeutic agents and promising delivery vectors
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Preliminary antifungal activity assay of selected chlorine-containing derivatives of xanthone and phenoxyethyl amines
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Simplified, serine‐rich theta‐defensin analogues as antitumour peptides
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The Chemometric Evaluation of Antitumor Activity of Novel Benzensulfonamide Derivatives Based on their Physiochemical Properties
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QSAR Analysis of Compounds Exhibiting General Anesthetics’ Properties
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QSAR Analysis of Selected Antimicrobial Structures Belonging to Nitro-derivatives of Heterocyclic Compounds
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Differential scanning calorimetry for authentication of edible fats and oils - What can we learn from the past to face the current challenges?
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Synthesis and biological evaluation of N-acylated tyramine sulfamates containing C-F bonds as steroid sulfatase inhibitors
PublikacjaSteroid sulfatase (STS) is responsible for the hydrolysis of biologically inactive sulfated steroids into their active un-sulfated forms and promotes the growth of various hormone-dependent cancers (e.g., breast cancer). Therefore, the STS enzyme is a promising therapeutic target for the treatment of steroid-sensitive cancers. Herein, we report the synthesis and biological evaluation of sulfamate analogs as potential STS inhibitors...
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Influence of S-Oxidation on Cytotoxic Activity of Oxathiole-Fused Chalcones
PublikacjaSynthesis, in vitro cytotoxic activity, and interaction with tubulin of oxidized, isomeric 1-(5-alkoxybenzo[d] [1,3]oxathiol-6-yl)-3-phenylprop-2-en-1-ones and 1-(6- alkoxybenzo[d][1,3]oxathiol-5-yl)-3-phenylprop-2-en-1- ones are described. Most of the compounds demonstrated cytotoxic activity at submicromolar concentrations. It was found that oxidation of sulfur atom of the oxathiole-fused chalcones strongly influenced activity...
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Synthesis and biological evaluation of fluorinated 3-phenylcoumarin-7-O-sulfamate derivatives as steroid sulfatase inhibitors
PublikacjaIn the present work, we report the initial results of our study on a series of 3-phenylcoumarin sulfamate-based compounds containing C-F bonds as a novel inhibitors of steroid sulfatase (STS). The new compounds are potent STS inhibitors, possessing more than 10 times higher inhibitory potency than coumarin-7-O-sulfamate. In the course of our investigation, compounds 2b and 2c demonstrated the highest inhibitory effect in the enzymatic...
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Novel anticancer strategy aimed at targeting shelterin complexes by the induction of structural changes in telomeric DNA: hitting two birds with one stone.
PublikacjaThe ends of chromosomes in mammals are composed of telomeric DNA containing TTAGGG repeats, which bind specific proteins called shelterins. This telomeric DNA together with shelterins form a cap that protects the ends of chromosomes from being recognized as sites of DNA damage and from chromosomal fusions. Many very successful antitumor drugs used in the treatment of cancer patients bind to DNA, some of them with a prominent sequence...
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Structural Factors Affecting Cytotoxic Activity of (E)-1-(Benzo[d ][1,3]oxathiol-6-yl)-3-phenylprop-2-en-1-one Derivatives
PublikacjaDerivatives of (E)-1-(5-alkoxybenzo[d][1,3]oxathiol-6-yl)-3-phenylprop-2-en-1-one (1) demonstrated exceptionally high in vitro cytotoxic activity, with IC50 values of the most active derivatives in the nanomolar range. To identify structural fragments necessary for the activity, several analogs deprived of selected fragments were prepared, and their cytotoxic activity was tested. It was found that the activity depends on combined effects...
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Synthesis and biological activity of ester derivatives of mycophenolic acid and acridines/acridones as potential immunosuppressive agents
PublikacjaImproved derivatives of mycophenolic acid (MPA) are necessary to reduce the frequency of adverse effects, this drug exerts in treated patients. In this study, MPA was coupled with N-(x-hydroxyalkyl)-9-acridone-4-carboxamides or N-(x-hydroxyalkyl)acridine-4-carboxamides to give respective ester conjugates upon Yamaguchi protocol. This esterification required protection of phenol group in MPA. Designed conjugates revealed higher...
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Fluctuation enhanced gas sensing using UV irradiated Au-nanoparticle-decorated WO3-nanowire films
PublikacjaWO3 nanowires (WO3-NWs) decorated with gold nanoparticles (AuNPs) were utilized in resistive gas sensor devices to detect ethanol by use of fluctuation enhanced sensing (FES). The experimental system records both DC resistance and fluctuations of the sensing film. Our data verify that the sensitivity and selectivity of the gas sensor are improved by applying FES when the sensor is stimulated with a combination of UV light and heating....
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Antiferromagnetic Order in the Rare-Earth Halide Perovskites CsEuBr3 and CsEuCl3
PublikacjaBulk CsEuBr3 and CsEuCl3 are experimentally shown to be magnetic semiconductors that order antiferromagnetically at Néel temperatures of 2.0 K and 1.0 K, respectively. Given that nanoparticles and thin films of CsEuCl3 have been reported to order ferromagnetically at a similar temperature, our observation of antiferromagnetic ordering in CsEuBr3 and CsEuCl3 expands the possible applications of halide perovskites to now include...
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PERFORMANCE OF THE PVT SOLAR COLLECTOR OPERATED WITH WATER –AL2O3 NANOFLUID
PublikacjaAn experimental investigation of the hybrid module photovoltaic panel -solar collector (PVT) cooled by water-Al2O3 nanofluids has been conducted. The weight fractions of the nanoparticles were 1% and 3%. Thermal efficiency, power efficiency and overall efficiency have been determined for artificial source of light and sunlight. No noticeable effect of the nanoparticle concentration on the overall efficiency of the PVT module has...