conducting polymers
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Polyaniline (PANI) belongs to a group of conducting polymers that show numerous properties useful in biomedical applications. Although PANI has long been studied in terms of interaction with human tissue, the published studies are mostly focused on composites of polyaniline with other polymers, not allowing for generalization of the obtained results. The present study is focused on the adhesion of human liver cells to a conducting and nonconducting polyaniline films. The ability of human liver cells to attach to both types of the tested surfaces was confirmed. Cell proliferation on the PANI surfaces was monitored in relation to material biocompatibility and to its practical applications. The results showed statistically significant differences in cell proliferation depending on the type of PANI film. The study thus points out the need to test materials in their neat forms, which allow for better generalization of the test results leading to their broader applications.
The cytocompatibility of cardiomyocytes derived from embryonic stem cells and neural progenitors, which were seeded on the surface of composite films made of graphene oxide (GO) and polypyrrole (PPy-GO) or poly(3,4-ethylenedioxythiophene) (PEDOT-GO) are reported. The GO incorporated in the composite matrix contributes to the patterning of the composite surface, while the electrically conducting PPy and PEDOT serve as ion-to-electron transducers facilitating electrical stimulation/sensing. The films were fabricated by a simple one-step electropolymerization procedure on electrically conducting indium tin oxide (ITO) and graphene paper (GP) substrates. Factors affecting the cell behaviour, i.e. the surface topography, wettability, and electrical surface conductivity, were studied. The PPy-GO and PEDOT-GO prepared on ITO exhibited high surface conductivity, especially in the case of the ITO/PPy-GO composite. We found that for cardiomyocytes, the PPy-GO and PEDOT-GO composites counteracted the negative effect of the GP substrate that inhibited their growth. Both the PPy-GO and PEDOT-GO composites prepared on ITO and GP significantly decreased the cytocompatibility of neural progenitors. The presented results enhance the knowledge about the biological properties of electroactive materials, which are critical for tissue engineering, especially in context stimuli-responsive scaffolds.
- MeSH
- bicyklické sloučeniny heterocyklické chemie MeSH
- elektrická vodivost * MeSH
- elektrochemie * MeSH
- grafit farmakologie MeSH
- kardiomyocyty cytologie účinky léků MeSH
- myši MeSH
- nervové kmenové buňky cytologie účinky léků MeSH
- neurogeneze účinky léků MeSH
- polymery chemie farmakologie MeSH
- pyrroly chemie MeSH
- voda chemie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The visualization of fingerprints on metal substrates is a problematic issue in contemporary criminology. Com-mon methods of visualization (powder methods) are fast and simple but not very effective for metallic substrates. If fingerprints are deposited on metallic media, the common-ly used methods are based on the reaction of the reagent with the fingerprint material, making the ridges of the pa-pillary lines visible and creating a positive image of the fingerprint. However, for these classical methods, the pro-gressive aging of the fingerprint poses a problem, resulting in the loss of identification information. This review is devoted to the use of a thin conducting polymer layers for better visualization of fingerprints on problematic metal surfaces, which are widespread in the criminology. The fingerprint on a metallic substrate behaves like a template: it masks those areas where papillary lines are present, thus inhibiting polymer deposition. The result is a negative image of the fingerprint which means that only areas where the surface of the substrate is not blocked by the fingerprint are visible. This simple method of the finger-print visualization, based on electrodeposited polymers is fast, inexpensive and reliable. It can represent a great help for criminal investigators.
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
- dusičnan stříbrný chemie MeSH
- elektrická vodivost MeSH
- kyslík chemie MeSH
- organická chemie metody 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
Bio-inspired conductive scaffolds composed of sodium hyaluronate containing a colloidal dispersion of water-miscible polyaniline or polypyrrole particles (concentrations of 0.108, 0.054 and 0.036% w/w) were manufactured. For this purpose, either crosslinking with N-(3-dimethylaminopropyl-N-ethylcarbodiimide hydrochloride and N-hydroxysuccinimid or a freeze-thawing process in the presence of poly(vinylalcohol) was used. The scaffolds comprised interconnected pores with prevailing porosity values of ~ 30% and pore sizes enabling the accommodation of cells. A swelling capacity of 92-97% without any sign of disintegration was typical for all samples. The elasticity modulus depended on the composition of the scaffolds, with the highest value of ~ 50 kPa obtained for the sample containing the highest content of polypyrrole particles. The scaffolds did not possess cytotoxicity and allowed cell adhesion and growth on the surface. Using the in vivo-mimicking conditions in a bioreactor, cells were also able to grow into the structure of the scaffolds. The technique of scaffold preparation used here thus overcomes the limitations of conductive polymers (e.g. poor solubility in an aqueous environment, and limited miscibility with other hydrophilic polymer matrices) and moreover leads to the preparation of cytocompatible scaffolds with potentially cell-instructive properties, which may be of advantage in the healing of damaged electro-sensitive tissues.
Intact heparin was characterized and determined in model samples, in infusion solutions and in blood plasma by capillary electrophoresis (CE) with contactless conductivity detection. The CE separation of polydisperse heparin took place in open silica capillaries, in electrolytes containing a polymer (hydroxyethyl)cellulose, poly(ethylene glycol) or dextran. The best separation of heparin from excess inorganic ions present in real samples was attained in a background electrolyte consisting of 0.8 M acetic acid and 1% (w/v) dextran (100 kDa). The limit of detection (LOD) was 1.3 µmol l-1. This electrolyte was used in determination of heparin in blood plasma and in infusion solutions.
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
Zosyntetizovali sa polyméry s odtlačkami molekúl na extrakciu 1-metyl-2-piperidínoetylesterov 2-metoxyfenylkarbámovej kyseliny, ktorá sa použila ako templát. Pri syntéze sa použili funkčné monoméry akrylamid a kyselina metakrylová. Pripravené polyméry sa testovali ako sorbenty na extrakciu tuhou fázou (MISPE). Študovala sa ich kapacita a selektivita k derivátom 1-metyl-2-piperidínoetylesterov alkoxyfenylkarbámových kyselín, ktoré sú lokálne anestetiká. Zároveň rovnakou metódou sa pripravili polyméry bez použitia templátu, čím sa mohli zistiť nešpecifické interakcie medzi sorbentom a skúmanými látkami. Polymér pripravený pomocou metakrylovej kyseliny sa použil na predkoncentráciu 1-metyl-2-piperidínoetylesteru 2-metoxyfenylkarbámovej kyseliny z ľudskej plazmy, do ktorej sa pridala uvedená látka (1 µg v 1 ml plazmy).
Molecularly imprinted polymers for 1-methyl-2-piperidinoethylester of 2-methoxyphenylcarbamic acid (template) have been synthesised. Acrylamide and methacrylic acids, respectively, were used as the functional monomers. Imprinted polymers were used as the sorbents for solid-phase extraction (MISPE). The capacity and selectivity of prepared imprinted polymers were investigated with the use of some derivatives of 1-methyl-2-piperidinethylesters of alkoxyphenylcarbamic acids. The non-imprinted (blank) polymers were prepared by the same way without a template to study the non-specific interactions. The molecularly imprinted polymer prepared from methacrylic acid was used to preconcentrate 1-methyl-2-piperidinoethylester of 2-methoxyphenylcarbamic acid and its analogues from spiked human plasma (1 µg in 1 ml of plasma).
This review summarizes recent trends in the construction of bioartificial vascular replacements, i.e. hybrid grafts containing synthetic polymeric scaffolds and cells. In these advanced replacements, vascular smooth muscle cells (VSMC) should be considered as a physiological component, although it is known that activation of the migration and proliferation of VSMC plays an important role in the onset and development of vascular diseases, and also in restenosis of currently used vascular grafts. Therefore, in novel bioartificial vascular grafts, VSMCs should be kept in quiescent mature contractile phenotype. This can be achieved by (1) appropriate physical and chemical properties of the material, such as its chemical composition, polarity, wettability, surface roughness and topography, electrical charge and conductivity, functionalization with biomolecules and mechanical properties, (2) appropriate cell culture conditions, such as composition of cell culture media and dynamic load, namely cyclic strain, and (3) the presence of a confluent, mature, semipermeable, non-thrombogenic and non-immunogenic endothelial cell (EC) barrier, covering the luminal surface of the graft and separating the VSMCs from the blood. Both VSMCs and ECs can also be differentiated from stem and progenitor cells of various sources. In the case of degradable scaffolds, the material will gradually be removed by the cells and will be replaced by their own new extracellular matrix. Thus, the material component in advanced blood vessel substitutes acts as a temporary scaffold that promotes regeneration of the damaged vascular tissue.
- MeSH
- buněčná diferenciace MeSH
- cévní protézy MeSH
- endoteliální buňky fyziologie patologie MeSH
- extracelulární matrix metabolismus MeSH
- kmenové buňky metabolismus patologie MeSH
- lidé MeSH
- myocyty hladké svaloviny fyziologie patologie MeSH
- nemoci cév patologie terapie MeSH
- polymery chemie MeSH
- proliferace buněk MeSH
- svaly hladké cévní patologie MeSH
- tkáňové podpůrné struktury MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
