Here, we describe a fluorescent assay developed to study competitive binding of the glycopeptide antibiotics to live bacteria cells. This assay demonstrated that the mechanism of action of the lipoglycopeptide antibiotics strongly depends on the hydrophobicity of the substitutes, with the best antibacterial activity of the glycopeptide antibiotics equally sharing properties of binding to D-Ala-D-Ala residues of the nascent peptidoglycan and to the membrane.
- MeSH
- antibakteriální látky metabolismus MeSH
- barvení a značení MeSH
- buněčná stěna mikrobiologie MeSH
- Enterococcus faecium metabolismus MeSH
- enterokoky rezistentní vůči vankomycinu metabolismus MeSH
- fluorescence MeSH
- glykopeptidy metabolismus MeSH
- lipoglykopeptidy chemie metabolismus MeSH
- mikrobiální testy citlivosti MeSH
- peptidoglykan metabolismus MeSH
- rhodaminy chemie MeSH
- Staphylococcus aureus metabolismus MeSH
- teikoplanin analogy a deriváty chemie metabolismus MeSH
- vankomycin chemie metabolismus MeSH
- vazba proteinů fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
Humic acids are often regarded as substances with a supramolecular structure which plays an important role in Nature. Their addition into hydrogels can affect their behavior and functioning in different applications. This work is focused on the properties of widely-used hydrogel based on agarose after addition of humic acids-the protonated H-form of humic acids and humic acids with methylated carboxylic groups. Hydrogels enriched by humic acids were studied in terms of their viscoelastic and transport properties. Rotational rheometry and methods employing diffusion cells were used in order to describe the influence of humic acids on the properties and behavior of hydrogels. From the point of view of rheology the addition of humic acids mainly affected the loss modulus corresponding to the relaxation of hydrogel connected with its flow. In the case of diffusion experiments, the transport of dyes (methylene blue and rhodamine) and metal ions (copper and nickel) through the hydrogel was affected by interactions between humic acids and the diffusion probes. The time lag in the hydrogel enriched by humic acids was prolonged for copper, methylene blue and rhodamine. In contrast, the presence of humic acids in hydrogel slightly increased the mobility of nickel. The strongest influence of the methylation of humic acids on diffusion was observed for methylene blue.
Nanoparticles have become popular in life sciences in the last few years. They have been produced in many variants and have recently been used in both biological experiments and in clinical applications. Due to concerns over nanomaterial risks, there has been a dramatic increase in investigations focused on safety research. The aim of this paper is to present the advanced testing of rhodamine-derived superparamagnetic maghemite nanoparticles (SAMN-R), which are used for their nontoxicity, biocompatibility, biodegradability, and magnetic properties. Recent results were expanded upon from the basic cytotoxic tests to evaluate cell proliferation and migration potential. Two cell types were used for the cell proliferation and tracking study: mouse embryonic fibroblast cells (3T3) and human mesenchymal stem cells (hMSCs). Advanced microscopic methods allowed for the precise quantification of the function of both cell types. This study has demonstrated that a dose of nanoparticles lower than 20 µg·cm-2 per area of the dish does not negatively affect the cells' morphology, migration, cytoskeletal function, proliferation, potential for wound healing, and single-cell migration in comparison to standard CellTracker™ Green CMFDA (5-chloromethylfluorescein diacetate). A higher dose of nanoparticles could be a potential risk for cytoskeletal folding and detachment of the cells from the solid extracellular matrix.
- MeSH
- biologické markery MeSH
- buněčné linie MeSH
- fibroblasty účinky léků metabolismus MeSH
- imunofenotypizace MeSH
- lidé MeSH
- magnetické nanočástice * chemie MeSH
- mezenchymální kmenové buňky účinky léků metabolismus MeSH
- myši MeSH
- pohyb buněk účinky léků MeSH
- proliferace buněk účinky léků MeSH
- průtoková cytometrie MeSH
- reaktivní formy kyslíku metabolismus MeSH
- rhodaminy chemie farmakologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
In the present work, we developed a novel needleless emulsion electrospinning technique that improves the production rate of the core/shell production process. The nanofibres are based on poly-ε-caprolactone (PCL) as a continuous phase combined with a droplet phase based on Pluronic F-68 (PF-68). The PCL-PF-68 nanofibres show a time-regulated release of active molecules. Needleless emulsion electrospinning was used to encapsulate a diverse set of compounds to the core phase [i.e. 5-(4,6-dichlorotriazinyl) aminofluorescein -PF-68, horseradish peroxidase, Tetramethylrhodamine-dextran, insulin growth factor-I, transforming growth factor-β and basic fibroblast growth factor]. In addition, the PF-68 facilitates the preservation of the bioactivity of delivered proteins. The system's potential was highlighted by an improvement in the metabolic activity and proliferation of mesenchymal stem cells. The developed system has the potential to deliver susceptible molecules in tissue-engineering applications.
- MeSH
- biokompatibilní materiály farmakologie MeSH
- dextrany chemie MeSH
- emulze chemie MeSH
- jehly MeSH
- kolagen typ II metabolismus MeSH
- křenová peroxidasa metabolismus MeSH
- mezenchymální kmenové buňky cytologie účinky léků metabolismus MeSH
- mezibuněčné signální peptidy a proteiny farmakologie MeSH
- miniaturní prasata MeSH
- nanovlákna chemie ultrastruktura MeSH
- poloxamer chemie MeSH
- polyestery chemie MeSH
- prasata MeSH
- proteiny aplikace a dávkování MeSH
- rhodaminy chemie MeSH
- tkáňové inženýrství metody MeSH
- tkáňové podpůrné struktury chemie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Isoprenoid cytokinins play a number of crucial roles in the regulation of plant growth and development. To study cytokinin receptor properties in plants, we designed and prepared fluorescent derivatives of 6-[(3-methylbut-2-en-1-yl)amino]purine (N6-isopentenyladenine, iP) with several fluorescent labels attached to the C2 or N9 atom of the purine moiety via a 2- or 6-carbon linker. The fluorescent labels included dansyl (DS), fluorescein (FC), 7-nitrobenzofurazan (NBD), rhodamine B (RhoB), coumarin (Cou), 7-(diethylamino)coumarin (DEAC) and cyanine 5 dye (Cy5). All prepared compounds were screened for affinity for the Arabidopsis thaliana cytokinin receptor (CRE1/AHK4). Although the attachment of the fluorescent labels to iP via the linkers mostly disrupted binding to the receptor, several fluorescent derivatives interacted well. For this reason, three derivatives, two rhodamine B and one 4-chloro-7-nitrobenzofurazan labeled iP were tested for their interaction with CRE1/AHK4 and Zea mays cytokinin receptors in detail. We further showed that the three derivatives were able to activate transcription of cytokinin response regulator ARR5 in Arabidopsis seedlings. The activity of fluorescently labeled cytokinins was compared with corresponding 6-dimethylaminopurine fluorescently labeled negative controls. Selected rhodamine B C2-labeled compounds 17, 18 and 4-chloro-7-nitrobenzofurazan N9-labeled compound 28 and their respective negative controls (19, 20 and 29, respectively) were used for in planta staining experiments in Arabidopsis thaliana cell suspension culture using live cell confocal microscopy.
- MeSH
- 4-chlor-7-nitrobenzofurazan farmakologie MeSH
- adenin analogy a deriváty chemie MeSH
- Arabidopsis metabolismus MeSH
- barvicí látky chemie MeSH
- cytokininy chemie farmakologie MeSH
- fluorescenční barviva chemie MeSH
- isopentenyladenosin chemická syntéza chemie farmakologie MeSH
- karbocyaniny chemie MeSH
- konfokální mikroskopie MeSH
- kukuřice setá metabolismus MeSH
- molekulární struktura MeSH
- proteiny huseníčku metabolismus MeSH
- puriny chemie MeSH
- receptory cytokinové antagonisté a inhibitory chemie MeSH
- regulace genové exprese u rostlin MeSH
- regulátory růstu rostlin metabolismus MeSH
- rhodaminy chemie MeSH
- semenáček metabolismus MeSH
- terpeny metabolismus MeSH
- vývoj rostlin MeSH
- Publikační typ
- časopisecké články MeSH
In the last few years, magnetically labeled cells have been intensively explored, and non-invasive cell tracking and magnetic manipulation methods have been tested in preclinical studies focused on cell transplantation. For clinical applications, it is desirable to know the intracellular pathway of nanoparticles, which can predict their biocompatibility with cells and the long-term imaging properties of labeled cells. Here, we quantified labeling efficiency, localization, and fluorescence properties of Rhodamine derivatized superparamagnetic maghemite nanoparticles (SAMN-R) in mesenchymal stromal cells (MSC). We investigated the stability of SAMN-R in the intracellular space during a long culture (20 days). Analyses were based on advanced confocal microscopy accompanied by atomic absorption spectroscopy (AAS) and magnetic resonance imaging. SAMN-R displayed excellent cellular uptake (24 h of labeling), and no toxicity of SAMN-R labeling was found. 83% of SAMN-R nanoparticles were localized in lysosomes, only 4.8% were found in mitochondria, and no particles were localized in the nucleus. On the basis of the MSC fluorescence measurement every 6 days, we also quantified the continual decrease of SAMN-R fluorescence in the average single MSC during 18 days. An additional set of analyses showed that the intracellular SAMN-R signal decrease was minimally caused by fluorophore degradation or nanoparticles extraction from the cells, main reason is a cell division. The fluorescence of SAMN-R nanoparticles within the cells was detectable minimally for 20 days. These observations indicate that SAMN-R nanoparticles have a potential for application in transplantation medicine.
- MeSH
- dextrany metabolismus MeSH
- fluorescenční spektrometrie MeSH
- intracelulární prostor metabolismus MeSH
- lidé MeSH
- magnetické nanočástice chemie MeSH
- mezenchymální kmenové buňky cytologie metabolismus MeSH
- molekulární sondy chemie metabolismus MeSH
- molekulární zobrazování metody MeSH
- rhodaminy chemie MeSH
- tuková tkáň cytologie MeSH
- viabilita buněk MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Metallic biomaterial alloys composed of nickel and titanium have unique thermal shape memory, superelastic, and high damping properties, which are widely used in the medicine. The major parameter evaluated in the studies regarding the behaviour of the material in the contact with organism or cells is biocompatibility. The aim of the studies is to clarify the differences in the proliferation, growth, and morphology especially in the cell cultures. The cytotoxicity is affected among other by release of the metal ions in the presence of the metal alloy, which is further dependent on the possible treatments of the material and the corrosive properties. To evaluate the cytotoxicity, wide range of tests including the Sulforhodamine B assay and MTT tests, expression profiles, cell survival tests such as apoptotic test are used. The review compares the cell behaviour in contact with the material alloys composed of nickel and titanium with respect to different materials composition and different surface treatment that affects the ion release. Even though the results published so far are controversial, almost all data suggest sufficient biocompatibility in medical use.
- MeSH
- apoptóza účinky léků MeSH
- biokompatibilní materiály chemie farmakologie MeSH
- endoteliální buňky pupečníkové žíly (lidské) cytologie účinky léků fyziologie MeSH
- kmenové buňky cytologie účinky léků fyziologie MeSH
- krysa rodu rattus MeSH
- kultivované buňky MeSH
- lidé MeSH
- myocyty hladké svaloviny cytologie účinky léků fyziologie MeSH
- nádorové buněčné linie MeSH
- nikl chemie farmakologie MeSH
- proliferace buněk účinky léků MeSH
- rhodaminy chemie MeSH
- titan chemie farmakologie MeSH
- tuková tkáň cytologie účinky léků fyziologie MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Interactions of humic acids (HAs) with two cationic dyes (methylene blue and rhodamine 6G) were studied using a unique combination of diffusion and partitioning studies in HAs, containing hydrogels and batch sorption experiments. In order to investigate the involvement of carboxyl groups of HAs in these interactions, all experiments were performed for both, the original lignite HAs and HAs with selectively methylated carboxyls. The results of the diffusion experiments confirm that the interactions between the solute and humic substances have a strong impact on the rate of diffusion process. Surprisingly, the effect is almost equally approved for original and methylated HAs. On the other hand, the results of batch sorption experiments show strong improvement of the sorption capacity (methylated HAs), which is explained by changed morphology of alkylated HAs. The comparison of the results of diffusion and adsorption experiments shows that the diffusion experiments simulate the transport of solutes in natural humics containing environment more reasonably.
- MeSH
- adsorpce MeSH
- difuze MeSH
- huminové látky * MeSH
- methylenová modř chemie MeSH
- rhodaminy chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Even though superresolution microscopy indicates that size of plasma membrane rafts is <20 nm, those structures have never been observed. Förster resonance energy transfer (FRET) is therefore still the most powerful optical method for characterization of such domains. In this letter we investigate relation between nanodomain affinity of a donor-acceptor (D/A) pair and the detectable nanodomain size/area. We show that probes with high affinity to the liquid-ordered (L(o)) phase are required for detecting domain sizes of a few nanometers, and/or domains that occupy a few percent of the bilayer area. A combination of donors and acceptors that prefer different phases is the more favorable approach. For instance, a D/A pair with the distribution constant of donors K(D) = 5 and acceptors K(A) = 0.01 can resolve a broad spectrum of nanodomain sizes. On the other hand, currently available donors and acceptors that prefer the same phase, either the liquid-disordered (L(d)) or L(o) phase, are not so convenient for determining domain sizes <20 nm. Here the detection limits of FRET experiments employing several commonly used D/A pairs have been investigated.
- MeSH
- časové faktory MeSH
- cholerový toxin chemie MeSH
- elektrony MeSH
- fykoerythrin chemie MeSH
- karbocyaniny chemie MeSH
- lipidové dvojvrstvy chemie MeSH
- membránové mikrodomény chemie MeSH
- metoda Monte Carlo MeSH
- nanočástice chemie MeSH
- perylen chemie MeSH
- reprodukovatelnost výsledků MeSH
- rezonanční přenos fluorescenční energie metody MeSH
- rhodaminy chemie MeSH
- sloučeniny boru chemie MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
