Fabrication of adsorbents with excellent adsorption capacity, outstanding stability, easy separation ability, excellent recyclability and widely generality for organic dyes removal from wastewater remains challenging. Herein, three-dimensional polyaniline/poly(vinyl alcohol)/montmorillonite (PANI/PVAL/MMT) hybrid aerogels with easy separation performance and highly effective reusable adsorption on both anionic and cationic dyes were fabricated by a simple in-situ polymerization method. As-prepared hybrid aerogels were characterized via infrared and Raman spectra, scanning electron microscopy, energy dispersive spectra mapping, small and wide-angle X-ray scattering, thermogravimetric analysis, mercury intrusion porosimetry and elemental analysis. The results showed that MMT particles were successfully incorporated into aerogel matrix. Well-defined hierarchical structure, where PANI nanofibers are coated on the skeleton wall, can be observed for PANI/PVAL/MMT when the incorporation amount of MMT was around 11.1 wt%. The adsorption performance of as-prepared hybrid aerogels on both anionic and cationic dyes was systemically carried out at different solution pH, adsorbent dosage and initial dye concentration. The data analysis showed that the adsorption process for PVAL/PANI/MMT aerogel for Reactive Black 5, methyl orange and safranin followed Freundlich isotherm and the maximum experimental adsorption capacities were found to be 199, 251 and 57.0 mg g-1 at 25 °C, respectively. Mechanism studies indicated that the electrostatic interaction is the main driving force for the adsorption of dyes. The results demonstrated that the fabricated hybrid aerogel is an efficient adsorbent for the removal of both anionic and cationic organic dyes.

• Publikační typ
• časopisecké články MeSH

Novel composite films combining biocompatible polysaccharides with conducting polyaniline (PANI) were prepared via the in-situ polymerization of aniline hydrochloride in the presence of sodium hyaluronate (SH) or chitosan (CH). The composite films possess very good cytocompatibility in terms of adhesion and proliferation of two lines of human induced pluripotent stem cells (hiPSC). Moreover, the cardiomyogenesis and even formation of beating clusters were successfully induced on the films. The proportion of formed cardiomyocytes demonstrated excellent properties of composites for tissue engineering of stimuli-responsive tissues. The testing also demonstrated antibacterial activity of the films against E. coli and PANI-SH was able to reduce bacterial growth from 2 × 105 to < 1 cfu cm-2. Physicochemical characterization revealed that the presence of polysaccharides did not notably influence conductivities of the composites being ∼1 and ∼2 S cm-1 for PANI-SH and PANI-CH respectively; however, in comparison with neat PANI, it modified their topography making the films smoother with mean surface roughness of 4 (PANI-SH) and 14 nm (PANI-CH). The combination of conductivity, antibacterial activity and mainly cytocompatibility with hiPSC opens wide application potential of these polysaccharide-based composites.

• MeSH
• aniliny chemie   MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• biokompatibilní materiály chemie   farmakologie   MeSH
• buněčná adheze účinky léků   MeSH
• buněčné linie MeSH
• chitosan chemie   MeSH
• elektrická vodivost MeSH
• Escherichia coli účinky léků   MeSH
• indukované pluripotentní kmenové buňky účinky léků   metabolismus   MeSH
• kyselina hyaluronová chemie   MeSH
• lidé MeSH
• nanokompozity chemie   MeSH
• polymerizace MeSH
• povrchové vlastnosti MeSH
• proliferace buněk účinky léků   MeSH
• Staphylococcus aureus účinky léků   MeSH
• tkáňové inženýrství metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Polypyrrole one-dimensional nanostructures (nanotubes, nanobelts and nanofibers) were prepared using three various dyes (Methyl Orange, Methylene Blue and Eriochrome Black T). Their high electrical conductivity (from 17.1 to 60.9 S cm-1), good thermal stability (in the range from 25 to 150 °C) and resistivity against ageing (half-time of electrical conductivity around 80 days and better) were used in preparation of lightweight and flexible composites with silicone for electromagnetic interference shielding in the C-band region (5.85-8.2 GHz). The nanostructures' morphology and chemical structure were characterized by scanning electron microscopy, Brunauer-Emmett-Teller specific surface measurement and attenuated total reflection Fourier-transform infrared spectroscopy. DC electrical conductivity was measured using the Van der Pauw method. Complex permittivity and AC electrical conductivity of respective silicone composites were calculated from the measured scattering parameters. The relationships between structure, electrical properties and shielding efficiency were studied. It was found that 2 mm-thick silicone composites of polypyrrole nanotubes and nanobelts shield almost 80% of incident radiation in the C-band at very low loading of conductive filler in the silicone (5% w/w). Resulting lightweight and flexible polypyrrole composites exhibit promising properties for shielding of electromagnetic interference in sensitive biological and electronic systems.

• MeSH
• azosloučeniny chemie   MeSH
• elektromagnetické záření * MeSH
• methylenová modř chemie   MeSH
• mikroskopie elektronová rastrovací MeSH
• nanostruktury chemie   účinky záření   ultrastruktura   MeSH
• nanotrubičky chemie   účinky záření   ultrastruktura   MeSH
• nanovlákna chemie   účinky záření   MeSH
• polymery chemie   účinky záření   MeSH
• pyrroly chemie   účinky záření   MeSH
• silikony chemie   účinky záření   MeSH
• Publikační typ
• časopisecké články MeSH

Changes in cholesterol concentration in the plasma membrane of presynaptic nerve terminals nonspecifically modulate glutamate transport and homeostasis in the central nervous system. Reduction of the cholesterol content in isolated rat brain nerve terminals (synaptosomes) using cholesterol-depleting agents decreases the glutamate uptake and increases the extracellular level of glutamate in nerve terminals. Extraction of cholesterol from the plasma membrane and its further removal from the synaptosomes by external magnetic field can be achieved by means of magnetic nanoparticles with immobilized cholesterol-depleting agent such as O-methyl-β-cyclodextrin (MCD). A simple approach is developed for preparation of maghemite (γ-Fe2O3) nanoparticles containing chemically bonded MCD. The method is based on preparation of a silanization agent containing MCD. It is synthesized by the reaction of triethoxy(3-isocyanatopropyl)silane with MCD. Base-catalyzed silanization of superparamagnetic γ-Fe2O3 provides a relatively stable colloid product containing 48μmol of MCDg(-1). MCD-modified γ-Fe2O3 nanoparticles decrease the initial rate of the uptake and accumulation of l-[(14)C]glutamate and increase the extracellular l-[(14)C]glutamate level in the preparation of nerve terminals. The effect of MCD-immobilized nanoparticles is the same as that of MCD solution; moreover, magnetic manipulation of the nanoparticles enables removal of bonded cholesterol.

• MeSH
• beta-cyklodextriny chemie   farmakologie   MeSH
• biologický transport účinky léků   MeSH
• buněčná membrána účinky léků   metabolismus   MeSH
• cholesterol izolace a purifikace   metabolismus   farmakologie   MeSH
• kinetika MeSH
• krysa rodu rattus MeSH
• kyselina glutamová metabolismus   MeSH
• magnetické nanočástice chemie   MeSH
• membránové potenciály účinky léků   MeSH
• mozek účinky léků   metabolismus   MeSH
• potkani Wistar MeSH
• presynaptické terminály účinky léků   metabolismus   MeSH
• radioizotopy uhlíku MeSH
• silany chemie   MeSH
• synaptozomy účinky léků   metabolismus   MeSH
• železité sloučeniny chemie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Conducting polyaniline can be prepared and modified using several procedures, all of which can significantly influence its applicability in different fields of biomedicine or biotechnology. The modifications of surface properties are crucial with respect to the possible applications of this polymer in tissue engineering or as biosensors. Innovative technique for preparing polyaniline films via in-situ polymerization in colloidal dispersion mode using four stabilizers (poly-N-vinylpyrrolidone; sodium dodecylsulfate; Tween 20 and Pluronic F108) was developed. The surface energy, conductivity, spectroscopic features, and cell compatibility of thin polyaniline films were determined using contact-angle measurement, the van der Pauw method, Fourier-transform infrared spectroscopy, and assay conducted on mouse fibroblasts, respectively. The stabilizers significantly influenced not only the surface and electrical properties of the films but also their cell compatibility. Sodium dodecylsulfate seems preferentially to combine both the high conductivity and good cell compatibility. Moreover, the films with sodium dodecylsulfate were non-irritant for skin, which was confirmed by their in-vitro exposure to the 3D-reconstructed human tissue model.

• MeSH
• aniliny škodlivé účinky   chemie   MeSH
• fibroblasty účinky léků   MeSH
• koloidy škodlivé účinky   chemie   MeSH
• membrány umělé * MeSH
• myši MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Polyaniline is a promising conducting polymer with still increasing application potential in biomedicine. Its surface modification can be an efficient way how to introduce desired functional groups and to control its properties while keeping the bulk characteristics of the material unchanged. The purpose of the study was to synthetize thin films of pristine conducting polyaniline hydrochloride, non-conducting polyaniline base and polyaniline modified with poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA) and investigate chosen parameters of their hemocompatibility. The modification was performed either by introduction of PAMPSA during the synthesis or by reprotonation of polyaniline base. The polyaniline hydrochloride and polyaniline base had no impact on blood coagulation and platelet adhesion. By contrast, the polyaniline reprotonated with PAMPSA completely hindered coagulation thanks to its interaction with coagulation factors Xa, Va and IIa. The significantly lower platelets adhesion was also found on this surface. Moreover, this film maintains its conductivity at pH of 6, which is an improvement in comparison with standard polyaniline hydrochloride losing most of its conductivity at pH of 4. Polyaniline film with PAMPSA introduced during synthesis had an impact on platelet adhesion but not on coagulation. The combined conductivity, anticoagulation activity, low platelet adhesion and improved conductivity at pH closer to physiological, open up new possibilities for application of polyaniline reprotonated by PAMPSA in blood-contacting devices, such as catheters or blood vessel grafts.

• MeSH
• aniliny * MeSH
• buněčná adheze * MeSH
• hemokoagulace * MeSH
• lidé MeSH
• spektrofotometrie ultrafialová MeSH
• trombocyty cytologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

gamma-Fe2O3 nanoparticles obtained by coprecipitation of Fe(II) and Fe(III) chlorides with a base and subsequent oxidation were coated with a shell of hydrophilic biocompatible poly(N,N-dimethylacrylamide) (PDMAAm). Various initiators were attached to the iron oxide surface to enable the use of the "grafting-from" approach for immobilization of PDMAAm. They included 2,2'-azobis(2-methylpropanimidamide) dihydrochloride (AMPA), 2,2'-azobis(N-hydroxy-2-methylpropanimidamide) dihydrochloride (ABHA) and 4-cyano-4-{[1-cyano-3-(N-hydroxycarbamoyl)-1-methylpropyl]azo}pentanoic acid (CCHPA). Engulfment of PDMAAm-coated y-Fe2O3 nanoparticles by murine J774.2 macrophages was investigated. Only some nanoparticles were engulfed by the macrophages. PDMAAm-AMPA-gamma-Fe2O3 and PDMAAm-ABHA-y-Fe2O3 nanoparticles were rapidly engulfed by the cells. In contrast, neat y-Fe2O3 and PDMAAm-CCHPA-gamma-Fe2O3 particles induced formation of transparent vacuoles indicating toxicity of the particles. Thus, PDMAAm-coated AMPA- and ABHA-gamma-Fe2O3 nanoparticles can be recommended as non-toxic labels for mammalian cells.

• MeSH
• akrylamidy chemie   farmakologie   MeSH
• buněčné linie MeSH
• fluorescenční mikroskopie MeSH
• hydrofobní a hydrofilní interakce účinky léků   MeSH
• magnetické jevy MeSH
• magnety * MeSH
• makrofágy cytologie   účinky léků   metabolismus   MeSH
• myši MeSH
• nanočástice chemie   ultrastruktura   MeSH
• polymerizace účinky léků   MeSH
• radiační rozptyl MeSH
• savci metabolismus   MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• světlo MeSH
• velikost částic MeSH
• železité sloučeniny farmakologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Iron oxide nanoparticles obtained by the coprecipitation of Fe(II) and Fe(III) salts and oxidation were coated with a novel poly(vinyl acetate-co-5-tert-(butylperoxy)-5-methylhex-1-en-3-yne-co-butyl acrylate-co-maleic anhydride) (PVBM) oligomer to ensure colloidal stability. The magnetic nanoparticles were thoroughly characterized by a range of physico-chemical methods, which proved the presence of the coating on the particles. Experiments with rat mesenchymal stem cells (rMSCs) confirmed that PVBM-coated gamma-Fe2O3 nanoparticles were not cytotoxic and that the average efficiency of stem cell labeling was good and comparable to that obtained with commercial agents. The cells labeled with PVBM-coated gamma-Fe2O3 nanoparticles displayed excellent contrast on magnetic resonance (MR) images. Such particles are thus promising for in vivo MR imaging of transplanted cells. Moreover, PVBM offers the possibility of additional modification by grafting compounds that reduce non-specific protein adsorption.

• MeSH
• barvení a značení metody   MeSH
• femur cytologie   MeSH
• kovové nanočástice chemie   MeSH
• krysa rodu rattus MeSH
• magnetická rezonanční spektroskopie MeSH
• magnetická rezonanční tomografie MeSH
• magnetismus MeSH
• mezenchymální kmenové buňky chemie   MeSH
• molekulární struktura MeSH
• povrchové vlastnosti MeSH
• transmisní elektronová mikroskopie MeSH
• viabilita buněk MeSH
• železité sloučeniny chemie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The polyaniline (PANI) base was ball-milled with silver nitrate in the solid state. Samples were prepared at various mole ratios of silver nitrate to PANI constitutional units ranging from 0 to 1.5 for three processing times, 0, 5, and 10 min. The emeraldine form of PANI was oxidized to pernigraniline, and the silver nitrate was reduced to metallic silver. Nitric acid is a byproduct, which may protonate the residual emeraldine and pernigraniline. The changes occurring in the structure of PANI are discussed on the basis of Fourier transform IR and Raman spectroscopies. Raman spectra revealed the formation of pernigraniline salt. The reaction between the two nonconducting components, emeraldine base and silver nitrate, produced a mixture of two conducting components, emeraldine or pernigraniline nitrate and metallic silver. The accompanying conductivity changes were determined. The increase in the conductivity of the original base, 10(-9) S cm(-1), up to 10(-2) S cm(-1) was found to depend on the mole ratio of silver nitrate to PANI base and on the processing time of the components in the ball mill.

• MeSH
• aniliny chemie   MeSH
• časové faktory MeSH
• chemické modely MeSH
• chemie organická metody   MeSH
• dusičnan stříbrný chemie   MeSH
• elektrická vodivost MeSH
• kyslík chemie   MeSH
• polymery chemie   MeSH
• Ramanova spektroskopie metody   MeSH
• spektroskopie infračervená s Fourierovou transformací metody   MeSH
• stříbro chemie   MeSH
• testování materiálů MeSH
• transmisní elektronová mikroskopie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Maghemite (gamma-Fe2O3) nanoparticles were obtained by the coprecipitation of Fe(II) and Fe (III) salts with ammonium hydroxide followed by oxidation with sodium hypochlorite. Solution radical polymerization of N,N-dimethylacrylamide(DMAAm) in the presence of maghemite nanoparticles yielded poly(N,N-dimethylacrylamide)(PDMAAm)-coated maghemite nanoparticles. The presence of PDMAAm on the maghemite particle surface was confirmed by elemental analysis and ATR FTIR spectroscopy. Other methods of nanoparticle characterization involved scanning and transmission electron microscopy, atomic adsorption spectroscopy (AAS), and dynamic light scattering (DLS). The conversion of DMAAm during polymerization and the molecular weight of PDMAAmbound to maghemite were determined by using gas and size-exclusion chromatography, respectively. The effect of ionic 4,4'-azobis(4-cyanovaleric acid) (ACVA) initiator on nanoparticle morphology was elucidated. The nanoparticles exhibited long-term colloidal stability in water or physiological buffer. Rat and human bone marrow mesenchymal stem cells (MSCs) were labeled with uncoated and PDMAAm-coated maghemite nanoparticles and with Endorem as a control. Uptake of the nanoparticles was evaluated by Prussian Blue staining, transmission electron microscopy, T(2)-MR relaxometry, and iron content analysis. Significant differences in labeling efficiency were found for human and rat cells. PDMAAm-modified nanoparticles demonstrated a higher efficiency of intracellular uptake into human cells in comparison with that of dextran-modified (Endorem) and unmodified nanoparticles. In gelatin, even a small number of labeled cells changed the contrast in MR images. PDMAAmcoatednanoparticles provided the highest T(2) relaxivity of all the investigated particles. In vivo MR imaging ofPDMAAm-modified iron oxide-labeled rMSCs implanted in a rat brain confirmed their better resolution compared with Endorem-labeled cells.

• MeSH
• akrylamidy chemie   MeSH
• barvení a značení metody   MeSH
• financování organizované MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• magnetická rezonanční tomografie MeSH
• mezenchymální kmenové buňky cytologie   metabolismus   ultrastruktura   MeSH
• nanočástice chemie   MeSH
• radiační rozptyl MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• transmisní elektronová mikroskopie MeSH
• viabilita buněk MeSH
• želatina metabolismus   MeSH
• železité sloučeniny chemická syntéza   chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• zvířata MeSH