Nesladek, M* Dotaz Zobrazit nápovědu
Efficient delivery of stabilized nucleic acids (NAs) into cells and release of the NA payload are crucial points in the transfection process. Here we report on the fabrication of a nanoscopic cellular delivery carrier that is additionally combined with a label-free intracellular sensor device, based on biocompatible fluorescent nanodiamond particles. The sensing function is engineered into nanodiamonds by using nitrogen-vacancy color centers, providing stable non-blinking luminescence. The device is used for monitoring NA transfection and the payload release in cells. The unpacking of NAs from a poly(ethyleneimine)-terminated nanodiamond surface is monitored using the color shift of nitrogen-vacancy centers in the diamond, which serve as a nanoscopic electric charge sensor. The proposed device innovates the strategies for NA imaging and delivery, by providing detection of the intracellular release of non-labeled NAs without affecting cellular processing of the NAs. Our system highlights the potential of nanodiamonds to act not merely as labels but also as non-toxic and non-photobleachable fluorescent biosensors reporting complex molecular events.
- MeSH
- buňky HT-29 MeSH
- DNA * MeSH
- lidé MeSH
- luminiscence MeSH
- myši inbrední DBA MeSH
- nanodiamanty * MeSH
- transfekce * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
In recent years, fluorescent nanodiamond (fND) particles containing nitrogen-vacancy (NV) centers gained recognition as an attractive probe for nanoscale cellular imaging and quantum sensing. For these applications, precise localization of fNDs inside of a living cell is essential. Here we propose such a method by simultaneous detection of the signal from the NV centers and the spectroscopic Raman signal from the cells to visualize the nucleus of living cells. However, we show that the commonly used Raman cell signal from the fingerprint region is not suitable for organelle imaging in this case. Therefore, we develop a method for nucleus visualization exploiting the region-specific shape of C-H stretching mode and further use k-means cluster analysis to chemically distinguish the vicinity of fNDs. Our technique enables, within a single scan, to detect fNDs, distinguish by chemical localization whether they have been internalized into cell and simultaneously visualize cell nucleus without any labeling or cell-fixation. We show for the first time spectral colocalization of unmodified high-pressure high-temperature fND probes with the cell nucleus. Our methodology can be, in principle, extended to any red- and near-infrared-luminescent cell-probes and is fully compatible with quantum sensing measurements in living cells.
- MeSH
- buněčné jádro ultrastruktura MeSH
- cytologické techniky MeSH
- fluorescenční barviva MeSH
- kultivované buňky MeSH
- lidé MeSH
- molekulární zobrazování metody MeSH
- nádorové buněčné linie MeSH
- nanodiamanty * MeSH
- Ramanova spektroskopie MeSH
- zubní dřeň cytologie diagnostické zobrazování MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Užívání nelegálních drog je tradičně považováno za patologický jev, který nevyhnutelně vede k závislosti a k dalšímu zdravotnímu, sociálnímu či ekonomickému poškození uživatele i jeho okolí. Výzkumy provedené v posledních desetiletích ovšem dokládají, že je možné i tyto látky užívat dlouhodobě kontrolovaným způsobem a pomocí uplatňování vhodných regulačních mechanismů účinně předcházet problémům, které jsou s užíváním drog běžně spojovány. Článek shrnuje dosavadní poznatky z výzkumu kontrolovaného užívání nelegálních drog (heroin, kokain, amfetaminy, metamfetaminy, marihuana, MDMA/extáze a halucinogeny): popsány jsou jednotlivé teoretické modely dosahování kontroly, které se liší v počtu ovlivňujících proměnných a v jejich významu pro získání a udržení kontroly, za klíčový prvek kontroly jsou bez ohledu na zkoumanou látku považovány regulační mechanismy, které se týkají všech aspektů užívání. Kontrolující se uživatelé vykazují pestrý rejstřík vzorců užívání, převažují méně rizikové a méně intenzivní vzorce užívání s vyloučením injekční aplikace, typický kontrolující se uživatel je mladý muž, který žije v partnerském vztahu, je svobodný a bezdětný. Mezi možné aplikační oblasti konceptu kontrolovaného užívání drog patří léčba závislosti a prevence.
A consumption of illegal drug is traditionally considered to be a pathological phenomenon that inevitably leads to a drug addiction and to health, social or economic damage to both users and their kith and kin. However, research studies that have been carried out during last decades show that long term use of illicit substances in a controlled way is possible and when following of appropriate control mechanisms it effectively prevents the aforementioned problems that are usually linked to the drug use. This article summarizes current knowledge about controlled use of illicit drugs (heroin, cocaine, amphetamines, methamphetamines, marijuana, MDMA/ecstasy and hallucinogens): Individual theoretical models of control achievement are described, which differs in number of influencing variables and in their impact on gaining and maintaining control. Control mechanisms related to all aspects of drug use are considered to be key elements of control, irrespective of particular substance. Self-controlling users demonstrate multifarious patterns of use. Less risky and less intensive methods of use without injection application are prevailing. A typical self-controlling user is an unmarried and childless young man who lives in a relationship. Possible areas that could benefit from the concept of controlled drug use include addiction treatment and prevention.
We show that fluorescent nanodiamonds (FNDs) are among the few types of nanosensors that enable direct optical reading of noncovalent molecular events. The unique sensing mechanism is based on switching between the negatively charged and neutral states of NV centers which is induced by the interaction of the FND surface with charged molecules.
Diamond nanoparticles (DNPs) are very attractive for biomedical applications, particularly for bioimaging. The aim of this study was to evaluate the impact of DNPs on neural cancer cells and thus to assess the possible application of DNPs for these cells imaging. For this purpose, the neuroblastoma SH-SY5Y cell line was chosen. Cells were cultured in medium with different concentrations (15, 50, 100 and 150 μg/ml) of DNPs. After 48 h of incubation, cell metabolic activity was evaluated by the XTT assay. For assessment of cellular metabolic activity, cells were also cultured on differently terminated nanocrystalline diamond (NCD) coatings in medium with 150 μg/ml of DNPs. Cell adhesion and morphology were evaluated by brightfield microscopy. Diamond nanoparticle internalization was determined by confocal microscopy. The obtained results showed that low concentrations (15, 50 and 100 μg/ml) of nanoparticles did not significantly affect the SH-SY5Y cell metabolic activity. However, a higher concentration (150 μg/ml) of DNPs statistically significantly reduced SH-SY5Y cell metabolic activity. After 48 h incubation with 150 μg/ml DNPs, cell metabolic activity was 23% lower than in medium without DNPs on standard tissue culture polystyrene.
- MeSH
- biokompatibilní potahované materiály chemická syntéza farmakologie MeSH
- buněčná adheze účinky léků MeSH
- buněčné kultury MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nanodiamanty chemie MeSH
- neuroblastom patologie MeSH
- proliferace buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Nucleation is a core scientific concept that describes the formation of new phases and materials. While classical nucleation theory is applied across wide-ranging fields, nucleation energy landscapes have never been directly measured at the atomic level, and experiments suggest that nucleation rates often greatly exceed the predictions of classical nucleation theory. Multistep nucleation via metastable states could explain unexpectedly rapid nucleation in many contexts, yet experimental energy landscapes supporting such mechanisms are scarce, particularly at nanoscale dimensions. In this work, we measured the nucleation energy landscape of diamond during chemical vapor deposition, using a series of diamondoid molecules as atomically defined protonuclei. We find that 26-carbon atom clusters, which do not contain a single bulk atom, are postcritical nuclei and measure the nucleation barrier to be more than four orders of magnitude smaller than prior bulk estimations. These data support both classical and nonclassical concepts for multistep nucleation and growth during the gas-phase synthesis of diamond and other semiconductors. More broadly, these measurements provide experimental evidence that agrees with recent conceptual proposals of multistep nucleation pathways with metastable molecular precursors in diverse processes, ranging from cloud formation to protein crystallization, and nanoparticle synthesis.
