The combination of different nanomaterials has been investigated during the past few decades and represents an exciting challenge for the unexpected emerging properties of the resulting nano-hybrids. Spermidine (Spd), a biogenic polyamine, has emerged as a useful functional monomer for the development of carbon quantum dots (CQDs). Herein, an electrostatically stabilized ternary hybrid, constituted of iron oxide-DNA (the core) and spermidine carbon quantum dots (CQDSpds, the shell), was self-assembled and fully characterized. The as-obtained nano-hybrid was tested on HeLa cells to evaluate its biocompatibility as well as cellular uptake. Most importantly, besides being endowed by the magnetic features of the core, it displayed drastically enhanced fluorescence properties in comparison with parent CQDSpds and it is efficiently internalized by HeLa cells. This novel ternary nano-hybrid with multifaceted properties, ranging from fluorescence to superparamagnetism, represents an interesting option for cell tracking.

• MeSH
• biotechnologie MeSH
• fluorescence MeSH
• HeLa buňky MeSH
• kvantové tečky chemie   metabolismus   MeSH
• lidé MeSH
• nanostruktury chemie   MeSH
• polyaminy chemie   metabolismus   MeSH
• statická elektřina MeSH
• uhlík chemie   metabolismus   MeSH
• železité sloučeniny chemie   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

A novel enzyme-free electrochemical immunosensor was developed for highly sensitive detection and quantification of human epididymis protein 4 (HE4) in human serum. For the first time, core/shell CdSe/ZnS quantum dots were conjugated with anti-HE4 IgG antibodies for subsequent sandwich-type immunosensing with superparamagnetic microparticles functionalized with anti-HE4 IgG antibodies, which allow rapid and efficient HE4 capture from the sample. Electrochemical detection of anti-HE4 IgG - HE4 - anti-HE4 IgGCdSe/ZnS immunocomplex was performed by recording the current response of Cd(II) ions, released from dissolved quantum dots at screen-printed carbon electrode (SPCE), modified with mercury or bismuth film. The linear range of the detection was from 20 pM to 40 nM with limit of detection of 12 pM using three times the standard deviation of blank criterion at mercury-film SPCE and from 100 pM to 2 nM with limit of detection of 89 pM at bismuth-film SPCE. Proposed electrochemical immunosensor meets the requirements for fast and sensitive quantification of HE4 biomarker in early stage of ovarian cancer and due to the proper sensitivity and specificity presents a promising alternative to enzyme-based probes used routinely in clinical diagnostics.

• MeSH
• biosenzitivní techniky * MeSH
• bismut chemie   MeSH
• časná detekce nádoru MeSH
• elektrochemické techniky * MeSH
• elektrody MeSH
• exprese genu MeSH
• imunoanalýza * MeSH
• imunokonjugáty chemie   metabolismus   MeSH
• kvantové tečky chemie   MeSH
• lidé MeSH
• nádorové biomarkery krev   genetika   MeSH
• nádory vaječníků krev   diagnóza   genetika   patologie   MeSH
• proteiny analýza   genetika   metabolismus   MeSH
• protilátky chemie   metabolismus   MeSH
• rtuť chemie   MeSH
• sloučeniny kadmia chemie   MeSH
• sloučeniny selenu chemie   MeSH
• sloučeniny zinku chemie   MeSH
• uhlík chemie   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

The widespread of bacterial infections including biofilms drives the never-ending quest for new antimicrobial agents. Among the great variety of nanomaterials, carbon dots (CDs) are the most promising antibacterial material, but still require the adjustment of their surface properties for enhanced activity. In this contribution, we report a facile functionalization method of carbon dots (CDs) by tetraalkylammonium moieties using diazonium chemistry to improve their antibacterial activity against Gram-positive and Gram-negative bacteria. CDs were modified by novel diazonium salts bearing tetraalkylammonium moieties (TAA) with different alkyl chains (C2, C4, C9, C12) for the optimization of antibacterial activity. Variation of the alkyl chain allows to reach the significant antibacterial effect for CDs-C9 towards Gram-positive Staphylococcus aureus (S. aureus) (MIC = 3.09 ± 1.10 μg mL-1) and Gram-negative Escherichia coli (E. coli) (MIC = 7.93 ± 0.17 μg mL-1) bacteria. The antibacterial mechanism of CDs-C9 is ascribed to the balance between the positive charge and hydrophobicity of the alkyl chains. TAA moieties are responsible for enhanced adherence on the bacterial cell membrane, its penetration and disturbance of physiological metabolism. CDs-C9 were not effective in the generation of reactive oxygen species excluding the oxidative damage mechanism. In addition, CDs-C9 effectively promoted the antibiofilm treatment of S. aureus and E. coli biofilms outperforming previously-reported CDs in terms of treatment duration and minimal inhibitory concentration. The good biocompatibility of CDs-C9 was demonstrated on mouse fibroblast (NIH/3T3), HeLa and U-87 MG cell lines for concentrations up to 256 μg mL-1. Collectively, our work highlights the correlation between the surface chemistry of CDs and their antimicrobial performance.

• MeSH
• antibakteriální látky * farmakologie   MeSH
• Escherichia coli MeSH
• gramnegativní bakterie MeSH
• grampozitivní bakterie metabolismus   MeSH
• myši MeSH
• stafylokokové infekce * MeSH
• Staphylococcus aureus MeSH
• uhlík chemie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

This study illustrates the synthesis of functionalized carbon quantum dots (CQDs) by the one-pot pyrolysis method. The functionalization agent used in CQD synthesis was poly l- lysine (PLL). Various physicochemical techniques were employed to confirm the successful formation of PLLCQD including High resolution transmission electron microscopy (HR-TEM), UV-Vis spectroscopy, fluorescence spectroscopy; Atomic force microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The size of PLLCQD was confirmed by HRTEM and AFM. The synthesized PLLCQD shows bright blue fluorescence and has a quantum yield of 19.35%. The highest emission band was observed at 471nm when excited to 370nm. The prepared PLLCQD exhibited excellent antibacterial activity against Escherichia coli and Staphylococcus aureus with inhibition zone 7-20 mm. The concentrations of 0.9 to 0.1gmL-1 were studied to determine minimum inhibitory concentration (MIC) by the agar well diffusion assay method. MIC of 0.2gml -1 concentration of PLLCQD is achieved. The anti-angiogenic activity of PLLCQD was determined using (Chick Chorioallantoic Membrane) CAM assay. CAM assay is a reliable in -vivo model to study angiogenesis also; many stimulators and inhibitors have been examined by this method. This study proves higher antibacterial efficiency of PLLCQD over non functionalized CQD. PLLCQD was successfully employed in bio-imaging of the bacterial cell through fluorescence microscopy. Further, PLLCQD displayed cytotoxic effect on endothelial cells and inhibited blood vessel formation in the CAM model.

• MeSH
• antibakteriální látky farmakologie   MeSH
• endoteliální buňky MeSH
• Escherichia coli MeSH
• kvantové tečky * chemie   MeSH
• lysin MeSH
• polylysin MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• uhlík chemie   MeSH
• Publikační typ
• časopisecké články MeSH

This study presents a toxicological evaluation of two types of carbon dots (CD), similar in size (<10 nm) but differing in surface charge. Whole-genome mRNA and miRNA expression (RNAseq), as well as gene-specific DNA methylation changes, were analyzed in human embryonic lung fibroblasts (HEL 12469) after 4 h and 24 h exposure to concentrations of 10 and 50 µg/mL (for positive charged CD; pCD) or 10 and 100 µg/mL (for negative charged CD, nCD). The results showed a distinct response for the tested nanomaterials (NMs). The exposure to pCD induced the expression of a substantially lower number of mRNAs than those to nCD, with few commonly differentially expressed genes between the two CDs. For both CDs, the number of deregulated mRNAs increased with the dose and exposure time. The pathway analysis revealed a deregulation of processes associated with immune response, tumorigenesis and cell cycle regulation, after exposure to pCD. For nCD treatment, pathways relating to cell proliferation, apoptosis, oxidative stress, gene expression, and cycle regulation were detected. The expression of miRNAs followed a similar pattern: more pronounced changes after nCD exposure and few commonly differentially expressed miRNAs between the two CDs. For both CDs the pathway analysis based on miRNA-mRNA interactions, showed a deregulation of cancer-related pathways, immune processes and processes involved in extracellular matrix interactions. DNA methylation was not affected by exposure to any of the two CDs. In summary, although the tested CDs induced distinct responses on the level of mRNA and miRNA expression, pathway analyses revealed a potential common biological impact of both NMs independent of their surface charge.

• MeSH
• apoptóza účinky léků   genetika   MeSH
• exprese genu účinky léků   genetika   MeSH
• extracelulární matrix genetika   MeSH
• fibroblasty účinky léků   MeSH
• kultivované buňky MeSH
• lidé MeSH
• messenger RNA genetika   MeSH
• metylace DNA účinky léků   genetika   MeSH
• mikro RNA genetika   MeSH
• nádory genetika   MeSH
• oxidační stres účinky léků   genetika   MeSH
• plíce účinky léků   MeSH
• proliferace buněk účinky léků   genetika   MeSH
• signální transdukce účinky léků   genetika   MeSH
• stanovení celkové genové exprese metody   MeSH
• uhlík farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Haemophilus Influenza leads to respiratory infections such as sinusitis, acute otitis media, pneumonia and bronchitis. In addition, it causes invasive infections such as cellulite, septic arthritis, and meningitis. Therefore, quick and sensitive detection of H. influenza is of great importance in medical microbiology. In this study, a novel DNA-based bioassay was developed to the monitoring of Haemophilus influenza genome in human plasma samples using binding of pDNA with cDNA. DNA hybridization strategy was used to investigation of DNAs binding. For this purpose, silver nanoparticle doped graphene quantum dots inks functionalized by D-penicillamine (Ag NPs-DPA-GQDs) were synthesized and deposited on the surface of glass carbon electrode (GCE). Also, gold nanoparticles functionalized with cysteamine (CysA-AuNPs) were deposited on the surface of the Ag-DPA-GQDs modified GCE. Afterward, thiolated DNA probe was immobilized on the surface of the modified electrode. DNA hybridization was monitored using square wave voltammetry (SWV) technique. Engineered genosensor indicated good performance with high specificity and sensitivity for detection of Haemophilus influenza genome. Under optimal conditions, linear range and low limit of quantitation (LLOQ) were obtained as target concentrations ranging from 1 pM-1 ZM and 1 ZM, respectively. The designed biosensor also showed high capability of discriminating one-base, two-base and three-base mismatched sequences. Also, the prepared genosensor could be easily regenerated and reused to evaluate hybridization process.

• MeSH
• biosenzitivní techniky MeSH
• elektrochemické techniky MeSH
• genom bakteriální * MeSH
• Haemophilus influenzae genetika   MeSH
• hybridizace nukleových kyselin metody   MeSH
• komplementární DNA * MeSH
• kovové nanočástice ultrastruktura   MeSH
• kvantové tečky MeSH
• lidé MeSH
• reprodukovatelnost výsledků MeSH
• volné cirkulující nukleové kyseliny * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The freshwater filamentous green oxyphotobacterium Prochlorothrix hollandica is an unusual oxygenic photoautotrophic cyanobacterium differing from most of the others by the presence of light-harvesting Pcb antenna binding both chlorophylls a and b and by the absence of phycobilins. The pigment-protein complexes of P. hollandica SAG 10.89 (CCAP 1490/1) were isolated from dodecylmaltoside solubilized thylakoid membranes on sucrose density gradient and characterized by biochemical, spectroscopic and immunoblotting methods. The Pcb antennae production is suppressed by high light conditions (>200 mumol photons m(-2) s(-1)) in P. hollandica. PcbC protein was found either in higher oligomeric states or coupled to PS I (forming antenna rings around PS I). PcbA and PcbB are most probably only very loosely bound to photosystems; we assume that these pigment-protein complexes function as low light-induced mobile antennae. Further, we have detected alpha-carotene in substantial quantities in P. hollandica thylakoid membranes, indicating the presence of chloroplast-like carotenoid synthetic pathway which is not present in common cyanobacteria.

• MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• fotosyntéza fyziologie   MeSH
• fotosystém I (proteinový komplex) izolace a purifikace   metabolismus   MeSH
• fotosystém II (proteinový komplex) izolace a purifikace   metabolismus   MeSH
• gelová chromatografie MeSH
• imunoblotting MeSH
• Prochlorophytes metabolismus   MeSH
• Prochlorothrix metabolismus   MeSH
• světlo MeSH
• tylakoidy metabolismus   ultrastruktura   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

We review the progress achieved during the recent five years in immunochemical biosensors (immunosensors) combined with nanoparticles for enhanced sensitivity. The initial part introduces antibodies as classic recognition elements. The optical sensing part describes fluorescent, luminescent, and surface plasmon resonance systems. Amperometry, voltammetry, and impedance spectroscopy represent electrochemical transducer methods; electrochemiluminescence with photoelectric conversion constitutes a widely utilized combined method. The transducing options function together with suitable nanoparticles: metallic and metal oxides, including magnetic ones, carbon-based nanotubes, graphene variants, luminescent carbon dots, nanocrystals as quantum dots, and photon up-converting particles. These sources merged together provide extreme variability of existing nanoimmunosensing options. Finally, applications in clinical analysis (markers, tumor cells, and pharmaceuticals) and in the detection of pathogenic microorganisms, toxic agents, and pesticides in the environmental field and food products are summarized.

• MeSH
• biosenzitivní techniky * MeSH
• imunoanalýza * MeSH
• lidé MeSH
• nanočástice chemie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

• MeSH
• chování MeSH
• molekulární biologie MeSH
• nemoci nervového systému MeSH
• nervový systém MeSH
• neurochemie MeSH
• neurofyziologie MeSH
• neurony MeSH
• neurovědy MeSH
• Publikační typ
• monografie MeSH

• Konspekt
• Fyziologie člověka a srovnávací fyziologie
• NLK Obory
• neurovědy
• biologie