quantum materials
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Nanoparticles are used in a wide range of disciplines due to their properties. The most common preparation is by physical and chemical synthesis, which uses a toxic chemicals that are not environmentally friendly and also limits the potential of the nanoparticles in their clinical applications. It is because of the negative properties of nanoparticles prepared by classical synthesis that a new type of synthesis comes to the fore. This is made possible by the ability of organisms to biosynthesize the nanoparticles either in the body or in the environment. Ability of the biosynthesis was demonstrated in a variety of microorganisms, but also in arthropods or even in mammals. Biosynthesis ability of organisms can be used both for the preparation of nanoparticles and for the reduction of contamination, since the raw materials for the synthesis are obtained from the environment. Biosynthesis by microorganisms could be a suitable alternative to conventional synthesis of quantum dots, mainly due to their low demands on the feedstock and the resulting biocompatibility of nanoparticles.
Semiconductor quantum dots (QDs) are nanoparticles in which charge carriers are three dimensionally or quantum confined. The quantum confinement provides size-tunable absorption bands and emission color to QDs. Also, the photoluminescence (PL) of QDs is exceptionally bright and stable, making them potential candidates for biomedical imaging and therapeutic interventions. Although fluorescence imaging and photodynamic therapy (PDT) of cancer have many advantages over imaging using ionizing radiations and chemo and radiation therapies, advancement of PDT is limited due to the poor availability of photostable and NIR fluorophores and photosensitizing (PS) drugs.
Synthesized nanoparticles often require fine fractionation according to shape, dimension, mass, chemical composition, charge, and other properties in order to become suitable for practical use. Quantum dots (QDs) are luminescent nanocrystals with narrow emission peaks. This property has been widely utilized for the multiplexed sensing and barcoding of microparticles. QDs with narrower emission peaks are preferred for such applications. The width of the emission peaks can be significantly reduced after purification. A newly developed preparative isotachophoretic method employs the dependence of spectral properties and electrophoretic mobility on the diameter of QDs. Separated fractions of QDs revealed narrower emission peaks (72% of the original width) and improved quantum yield (two-fold). The usefulness of the developed isotachophoresis for purification and analysis of other nanostructures, for example, plasmonic nanoparticles and nanobioconjugates, is expected, too.
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
BACKGROUND AND AIM: Amniotic membrane-derived mesenchymal stem cells (hAM-dMSCs) are a potential source of mesenchymal stem cells which could be used to repair skin damage. The use of mesenchymal stem cells to repair skin damage requires safe, effective and biocompatible agents to evaluate the effectiveness of the result. Quantum dots (QDs) composed of CdSe/ZnS are semiconductor nanocrystals with broad excitation and narrow emission spectra, which have been considered as a new chemical and fluorescent substance for non-invasively labeling different cells in vitro and in vivo. This study investigated the cytotoxic effects of QDs on hAM-dMSCs at different times following labeling. METHODS: Using 0.75, 1.5 and 3.0 μL between quantum dots, labeled human amniotic mesenchymal stem cells were collected on days 1, 2 and 4 and observed morphological changes, performed an MTT cell growth assay and flow cytometry for mesenchymal stem cells molecular markers. RESULTS: Quantum dot concentration 0.75 μg/mL labeled under a fluorescence microscope, cell morphology was observed, The MTT assay showed cells in the proliferative phase. Flow cytometry expression CD29, CD31, CD34, CD44, CD90, CD105 and CD106. CONCLUSIONS: Within a certain range of concentrations between quantum dots labeled human amniotic mesenchymal stem cells has good biocompatibility.
- MeSH
- amnion cytologie MeSH
- barvení a značení metody MeSH
- biokompatibilní materiály metabolismus MeSH
- biotest metody MeSH
- fluorescenční mikroskopie metody MeSH
- kvantové tečky škodlivé účinky metabolismus MeSH
- lidé MeSH
- mezenchymální kmenové buňky metabolismus MeSH
- techniky in vitro MeSH
- testování materiálů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
In this study, enhancement of the electrochemical signals of etoposide (ETO) measured by differential pulse voltammetry (DPV) by modifying a glassy carbon electrode (GCE) with carbon quantum dots (CQDs) is demonstrated. In comparison with a bare GCE, the modified GCE exhibited a higher sensitivity towards electrochemical detection of ETO. The lowest limit of detection was observed to be 5 nM ETO. Furthermore, scanning electron microscopy (SEM), fluorescence microscopy (FM), and electrochemical impedance spectroscopy (EIS) were employed for the further study of the working electrode surface after the modification with CQDs. Finally, the GCE modified with CQDs under optimized conditions was used to analyse real samples of ETO in the prostate cancer cell line PC3. After different incubation times (1, 3, 6, 9, 12, 18 and 24 h), these samples were then prepared prior to electrochemical detection by the GCE modified with CQDs. High performance liquid chromatography with an electrochemical detection method was employed to verify the results from the GCE modified with CQDs.
- MeSH
- elektrochemie přístrojové vybavení metody MeSH
- elektrody MeSH
- etoposid analýza chemie farmakologie MeSH
- kvantové tečky chemie MeSH
- lidé MeSH
- limita detekce MeSH
- nádorové buněčné linie MeSH
- povidon chemie MeSH
- sklo chemie MeSH
- uhlík chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Interaction between semiconductor nanocrystals, cadmium telluride quantum dots (CdTe QDs) capped with mercaptosuccinic acid (MSA) and metallothionein (MT) was investigated. MSA-capped CdTe QDs were synthesized in aqueous solution. Mixture of MT and MSA-capped CdTe QDs has been investigated by various analytical methods as follows: tris-tricine gel electrophoresis, fluorescence evaluation and electrochemical detection of catalysed hydrogen evolution. The obtained results demonstrate that MSA-capped CdTe QDs and MT do not create firmly bound stabile complex. However, weak electrostatic interactions contribute to the interaction of MT with MSA-capped CdTeQDs. It can be concluded that QDs size influences the QDs and MT interaction. The smallest QDs had the highest affinity to MT and vice versa.
- MeSH
- elektrochemické techniky MeSH
- fluorescenční spektrometrie MeSH
- králíci MeSH
- kvantové tečky * MeSH
- metalothionein chemie MeSH
- molekulární struktura MeSH
- nanočástice * MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Quantum dots (QDs) are one of the most promising nanomaterials, due to their size-dependent characteristics as well as easily controllable size during the synthesis process. They are promising label material and their interaction with biomolecules is of great interest for science. In this study, CdTe QDs were synthesized under optimal conditions for 2 nm size. Characterization and verification of QDs synthesis procedure were done by fluorimetric method and with CE. Afterwards, QDs interaction with chicken genomic DNA and 500 bpDNA fragment was observed employing CE-LIF and gel electrophoresis. Performed interaction relies on possible matching between size of QDs and major groove of the DNA, which is approximately 2.1 nm.
- MeSH
- DNA chemie metabolismus MeSH
- elektroforéza kapilární metody MeSH
- fluorescenční spektrometrie metody MeSH
- kur domácí MeSH
- kvantové tečky chemie metabolismus MeSH
- sloučeniny kadmia chemie metabolismus MeSH
- telur chemie metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Quantum dots are an emerging nanomaterial with broad use in technical disciplines; however, their application in the field of biomedicine becomes also relevant and significant possibilities have appeared since the discovery in 1980s. OBJECTIVE: The current review is focused on the therapeutic applications of quantum dots which become an emerging use of the particles. They are introduced as potent carriers of drugs and as a material well suited for the diagnosis of disparate pathologies like visualization of cancer cells or pathogenic microorganisms. CONCLUSION: Quantum dots toxicity and modifications for the toxicity reduction are discussed here as well. Survey of actual papers and patents in the field of quantum dots use in the biomedicine is provided.
The implementation of quantum dots in analytical chemistry has already advanced from basic research activities to routine applications of commercially available fluorescent agents present in sophisticated assays kits. Nevertheless, a further development of new preparation and characterization methods of nanoparticles is still required to increase the sensitivity of analytical methods substantially. Thus, in many bioanalytical applications, important molecules such as DNA, proteins, and antibodies are routinely conjugated with fluorescent tags to reach even the absolute sensitivity, that is, the capability to detect a single molecule in complex matrices. Semiconductor quantum dots have already proved to be suitable components of highly luminescent tags, probes, and sensors with broad applicability in analytical chemistry. Quantum dots provide high extinction coefficients together with wide ranges of excitation wavelengths, size- and composition-tunable emissions, narrow and symmetric emission spectra, good quantum yields, relatively long size-dependent luminescence lifetime, and low photobleaching. Most of these properties are superior when compared with conventional organic fluorescent dyes. In this chapter, optimized procedures for the preparation of water-dispersed CdTe quantum dots; their coatings and conjugation reactions with antibodies, DNA, and macrocycles; and their analyses by capillary electrophoresis are described. The potential of capillary electrophoresis for fast analyses of nanoparticles, their conjugates with antibodies and immunocomplexes with targeted antigens, is demonstrated as an example.
- MeSH
- elektroforéza kapilární metody MeSH
- fluorescenční barviva chemie MeSH
- kvantové tečky chemie MeSH
- luminiscenční měření metody MeSH
- nanočástice MeSH
- nanotechnologie MeSH
- proteiny chemie MeSH
- protilátky chemie MeSH
- rezonanční přenos fluorescenční energie metody MeSH
- sloučeniny kadmia chemie MeSH
- telur chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
