Innovative nanotechnology aims to develop particles that are small, monodisperse, smart, and do not cause unintentional side effects. Uniform magnetic Fe3O4 nanoparticles (12 nm in size) were prepared by thermal decomposition of iron(III) oleate. To make them colloidally stable and dispersible in water and cell culture medium, they were modified with phosphonic acid- (PA) and hydroxamic acid (HA)-terminated poly(ethylene glycol) yielding PA-PEG@Fe3O4 and HA-PEG@Fe3O4 nanoparticles; conventional γ-Fe2O3 particles were prepared as a control. Advanced techniques were used to evaluate the properties and safety of the particles. Completeness of the nanoparticle coating was tested by real-time polymerase chain reaction. Interaction of the particles with primary human peripheral blood cells, cellular uptake, cytotoxicity, and immunotoxicity were also investigated. Amount of internalized iron in peripheral blood mononuclear cells was 72, 38, and 25 pg Fe/cell for HA-PEG@Fe3O4, γ-Fe2O3, and PA-PEG@Fe3O4, respectively. Nanoparticles were localized within the cytoplasm and in the extracellular space. No cytotoxic effect of both PEGylated nanoparticles was observed (0.12-75 μg/cm2) after 24 and 72-h incubation. Moreover, no suppressive effect was found on the proliferative activity of T-lymphocytes and T-dependent B-cell response, phagocytic activity of monocytes and granulocytes, and respiratory burst of phagocytes. Similarly, no cytotoxic effect of γ-Fe2O3 particles was observed. However, they suppressed the proliferative activity of T-lymphocytes (75 μg/cm2, 72 h) and also decreased the phagocytic activity of monocytes (15 μg/cm2, 24 h; 3-75 μg/cm2, 72 h). We thus show that newly developed particles have great potential especially in cancer diagnostics and therapy.
- MeSH
- cytokiny metabolismus MeSH
- fagocytóza účinky léků imunologie MeSH
- kultivované buňky MeSH
- kyseliny fosforité chemie MeSH
- kyseliny hydroxamové chemie MeSH
- leukocyty mononukleární účinky léků imunologie patologie MeSH
- lidé MeSH
- magnetické nanočástice chemie toxicita MeSH
- nanomedicína metody MeSH
- polyethylenglykoly chemie MeSH
- povrchové vlastnosti MeSH
- proliferace buněk účinky léků MeSH
- respirační vzplanutí účinky léků imunologie MeSH
- velikost částic MeSH
- viabilita buněk účinky léků imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Staphylococcus aureus plasmids are the main factor in the spreading of antibacterial resistance among bacterial strains that has emerged on a worldwide scale. Plasmids recovered from 12 clinical and food isolates of S. aureus were treated with 10 mM free lanthanide Nd(3+) ions (non-enzymatic cleavage agent) in Hepes buffer (pH 7.5) at 70 °C. Topological forms of plasmids-closed circular (ccc), open circular (oc), and linear (lin)-produced by cleavage at different times were separated using pulsed-field agarose gel electrophoresis. The method is proposed to detect and differentiate several plasmids in the same bacterial strain according to their size.
DNA amplification by real-time polymerase chain reaction (RT-PCR) was used for the evaluation of efficiency of polymer coating of magnetic hydrophilic poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) (P(HEMA-co-GMA)) and poly(glycidyl methacrylate) (PGMA) microspheres with/without carboxyl groups. The inhibition effect of magnetic microspheres on real-time polymerase chain reaction (RT-PCR) course was evaluated by regression analysis after the addition of different concentrations of tested microspheres to PCR mixtures. Microspheres mostly did not interfere in RT-PCR till the concentration 50 µg/25 µl PCR mixture. No relationship between Fe content (and microsphere diameter) and inhibition effect was found. Microspheres containing carboxyl groups extinguished the fluorescence at lower concentrations (10-20 µg/25 µl PCR mixture) without inhibition of DNA amplification as PCR products were detected using agarose gel electrophoresis. Negative effect of maghemite on PCR course was partially reduced by coating of magnetic core by silica or polymers. Two inhibition mechanisms of DNA amplification were discussed in this work.
- MeSH
- DNA bakterií analýza genetika MeSH
- elektroforéza v agarovém gelu MeSH
- kvantitativní polymerázová řetězová reakce * MeSH
- kyseliny polymethakrylové chemie MeSH
- magnetické nanočástice chemie MeSH
- mikrosféry * MeSH
- molekulární patologie metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Reduced microbial diversity has been associated with inflammatory bowel disease (IBD) and probiotic bacteria have been proposed for its prevention and/or treatment. Nevertheless, comparative studies of strains of the same subspecies for specific health benefits are scarce. Here we compared two Bifidobacterium longum ssp. longum strains for their capacity to prevent experimental colitis. METHODS: Immunomodulatory properties of nine probiotic bifidobacteria were assessed by stimulation of murine splenocytes. The immune responses to B. longum ssp. longum CCM 7952 (Bl 7952) and CCDM 372 (Bl 372) were further characterized by stimulation of bone marrow-derived dendritic cell, HEK293/TLR2 or HEK293/NOD2 cells. A mouse model of dextran sulphate sodium (DSS)-induced colitis was used to compare their beneficial effects in vivo. RESULTS: The nine bifidobacteria exhibited strain-specific abilities to induce cytokine production. Bl 372 induced higher levels of both pro- and anti-inflammatory cytokines in spleen and dendritic cell cultures compared to Bl 7952. Both strains engaged TLR2 and contain ligands for NOD2. In a mouse model of DSS-induced colitis, Bl 7952, but not Bl 372, reduced clinical symptoms and preserved expression of tight junction proteins. Importantly, Bl 7952 improved intestinal barrier function as demonstrated by reduced FITC-dextran levels in serum. CONCLUSIONS: We have shown that Bl 7952, but not Bl 372, protected mice from the development of experimental colitis. Our data suggest that although some immunomodulatory properties might be widespread among the genus Bifidobacterium, others may be rare and characteristic only for a specific strain. Therefore, careful selection might be crucial in providing beneficial outcome in clinical trials with probiotics in IBD.
- MeSH
- Bifidobacterium klasifikace fyziologie MeSH
- dendritické buňky mikrobiologie patologie MeSH
- HEK293 buňky MeSH
- imunoenzymatické techniky MeSH
- kolitida chemicky indukované prevence a kontrola MeSH
- lidé MeSH
- modely nemocí na zvířatech * MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- probiotika farmakologie MeSH
- signální adaptorový protein Nod2 genetika metabolismus MeSH
- síran dextranu toxicita MeSH
- střeva mikrobiologie patofyziologie MeSH
- toll-like receptor 2 genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Superparamagnetic particles have been attractive for molecular diagnostics and analytical chemistry applications due to their unique magnetic properties and their ability to interact with various biomolecules of interest. This paper presents a critical overview of magnetic nano- and microparticles used as a solid phase for extraction and purification of DNAs. The mechanisms of DNA binding to the surface of functionalised magnetic particles are described. The most widely used materials including silica supports, organic polymers and other materials, mostly containing magnetite or paramagnetic metallic elements are reviewed. The main application areas of magnetic particles for DNA separation are briefly described.
Eleven strains of Lactobacillus collected in the Culture Collection of Dairy Microorganisms (CCDM) were evaluated for selected probiotic properties such as survival in gastrointestinal fluids, antimicrobial activity, and competition with non-toxigenic Escherichia coli O157:H7 for adhesion on Caco-2 cells. The viable count of lactobacilli was reduced during 3-h incubation in gastric fluid followed by 3-h incubation in intestinal fluid. All strains showed antimicrobial activity and the three most effective strains inhibited the growth of at least 16 indicator strains. Antimicrobial metabolites of seven strains active against Lactobacillus and Clostridium indicator strains were found to be sensitive to proteinase K and trypsin, which indicates their proteinaceous nature. The degree of competitive inhibition of non-toxigenic E. coli O157:H7 adhesion on the surface of Caco-2 cells was strain-dependent. A significant decrease (P < 0.05) in the number of non-toxigenic E. coli O157:H7 adhering to Caco-2 cells was observed with all lactobacilli. Three strains were selected for additional studies of antimicrobial activity, i.e., Lactobacillus gasseri CCDM 215, Lactobacillus acidophilus CCDM 149, and Lactobacillus helveticus CCDM 82.
- MeSH
- antibióza * MeSH
- antiinfekční látky metabolismus MeSH
- bakteriální adheze MeSH
- Caco-2 buňky MeSH
- epitelové buňky mikrobiologie MeSH
- Escherichia coli O157 fyziologie MeSH
- Lactobacillus růst a vývoj fyziologie MeSH
- lidé MeSH
- mikrobiální viabilita účinky léků MeSH
- probiotika farmakologie MeSH
- žaludeční šťáva mikrobiologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Wedelolactone is one of the active plant polyphenolic compounds. Anti-tumor effects of this drug have been demonstrated recently. We have described that wedelolactone acts as catalytic inhibitor of DNA topoisomerase IIα. The aim of this study was to further characterize the mechanism of its anti-tumor effects. We showed that wedelolactone inhibits binding of DNA topoisomerase IIα to plasmid DNA and antagonizes formation of etoposide-induced DNA cleavage complex. The inhibition of topoisomerase IIα by wedelolactone is reversible by excess of the enzyme but not DNA. The in vitro inhibitory effect of wedelolactone on the topoisomerase IIα activity is redox-dependent as it diminished in the presence of reducing agents. Cytotoxicity of wedelolactone was partially inhibited by N-acetylcysteine and glutathione ethyl ester in breast cancer MDA-MB-231 and MDA-MB-468 cells while the inhibitory effect of catalase was observed only in the former cell line. Finally, we found that wedelolactone can be oxidized in the presence of copper ions resulting in DNA strand break and abasic site formation in vitro. However, wedelolactone induced neither DNA damage in MDA-MB-231 cells nor mutations in bacterial cells detectable by Ames test suggesting that wedelolactone may not be an effective inducer of DNA damage. We conclude that the topoisomerase IIα inhibitory- and DNA damaging activities of wedelolactone in vitro depend on its redox state. Pro-oxidant activity could, however, explain only part of wedelolactone-induced cytotoxicity. Therefore, the major cellular target(s) of wedelolactone and the exact mechanism of wedelolactone-induced cytotoxicity still remain to be identified.
- MeSH
- acetylcystein MeSH
- antigeny nádorové metabolismus MeSH
- DNA vazebné proteiny antagonisté a inhibitory metabolismus MeSH
- DNA-topoisomerasy typu II metabolismus MeSH
- glutathion analogy a deriváty MeSH
- imunoblotting MeSH
- katalasa MeSH
- kumariny chemie metabolismus farmakologie MeSH
- lidé MeSH
- molekulární struktura MeSH
- NAD metabolismus MeSH
- nádorové buněčné linie MeSH
- nádory prsu farmakoterapie MeSH
- oxidace-redukce MeSH
- protinádorové látky chemie metabolismus farmakologie MeSH
- techniky in vitro MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Magnetic La(0.75)Sr(0.25)MnO(3) nanoparticles possessing an approximately 20-nm-thick silica shell (LSMO(0.25)@SiO(2) ) were characterised and tested for the isolation of PCR-ready bacterial DNA. The results presented here show that the nanoparticles do not interfere in PCR. DNA was apparently reversibly adsorbed on their silica shell from the aqueous phase system (16% PEG 6000-2 M NaCl). The method proposed was used for DNA isolation from complex food samples (dairy products and probiotic food supplements). The isolated DNA was compatible with PCR. The main advantages of the nanoparticles tested for routine use were their high colloidal stability allowing a more precise dosage and therefore high reproducibility of DNA isolation.
- MeSH
- DNA bakterií chemie izolace a purifikace MeSH
- Lactobacillus cytologie genetika MeSH
- lanthan chemie MeSH
- magnetické jevy MeSH
- magnetismus MeSH
- nanočástice chemie MeSH
- oxid křemičitý chemie MeSH
- oxidy chemie MeSH
- polymerázová řetězová reakce MeSH
- sloučeniny manganu chemie MeSH
- stroncium chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
