scholarly journals The Colloidal Quantum Dots Suitability for Long Term Cell Imaging

2018 ◽  
Vol 15 (2) ◽  
pp. 6275-6281
Author(s):  
Patricia M. A. Farias ◽  
André Galembeck ◽  
Raquel Milani ◽  
Wilson S. Mendonca ◽  
Andreas Stingl
Keyword(s):  
Quantum Dots ◽  
Glial Cells ◽  
Aqueous Suspension ◽  
High Rate ◽  
Cellular Mechanisms ◽  
Interaction Kinetics ◽  
Term Monitoring ◽  
Observation Period

Fluorescent semiconductor nanoparticles in tree-dimensional quantum confinement, quantum dots (QDs), synthesized in aqueous medium, and functionalized with polyethylene glycol, were used as nonspecific nanosized probes for the long-term imaging of glial cells. In vitro living healthy as well as cancer glial cells were labelled by direct insertion of a small volume of QDs contained in aqueous suspension into the culture wells. A long-term monitoring (over 7 days) of the cells was performed and no evidence of cell fixation and/or damage was observed. Two control groups, healthy and non-healthy glial cells, were used to compare cell viability. During the observation period, labelled cells kept the same behavior compared to non-labelled control samples. To our knowledge, this is the first report of the viability of quantum dots for long-term imaging of living cells. This opens a large range of possibilities related to a better understand of cellular mechanisms, which till now was not achieved by any other fluorescent probe. The study also permitted the observation of two distinct interaction kinetics between cells and QDs. Healthy glial cells were mainly labelled at their surface, while non-healthy glial cells have shown a high rate in the uptake of QDs.

scholarly journals Colloidal quantum dots suitability for long term cell imaging

2018 ◽  
Author(s):  
Patricia M. A. Farias ◽  
André Galembeck ◽  
Raquel Milani ◽  
Wilson S. Mendonca ◽  
Andreas Stingl
Keyword(s):  
Quantum Dots ◽  
Polyethylene Glycol ◽  
Cell Viability ◽  
Glial Cells ◽  
Aqueous Suspension ◽  
High Rate ◽  
Term Monitoring ◽  
Observation Period

AbstractFluorescent semiconductor nanoparticles in tree-dimensional quantum confinement, quantum dots (QDs), synthesized in aqueous medium, and functionalized with polyethylene glycol, were used as probes for the long-term imaging of glial cells. In vitro living healthy as well as cancer glial cells were labelled by direct insertion of a small volume of QDs contained in aqueous suspension into the culture wells. A long-term monitoring (over 7 days) of the cells was performed and no evidence of cell fixation and/or damage was observed. Two control groups, healthy and cancer glial cells, were used to compare cell viability. During the observation period, labelled and non labelled cells presented the same dynamics and no difference was observed regarding cell viability. To our knowledge, this is the first report of the viability of hydrophilic prepared quantum dots without any further surface treatment than the polyethylene-glycol coverage for the long-term imaging of living cells. Further, the study also permitted the observation of two distinct interaction mechanisms between cells and QDs. Healthy glial cells were mainly labelled at their surface, while non-healthy glial cells have shown a high rate in the uptake of QDs.

scholarly journals Loading Graphene Quantum Dots into Optical-Magneto Nanoparticles for Real-Time Tracking In Vivo

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2191 ◽  
Author(s):  
Yu Wang ◽  
Nan Xu ◽  
Yongkai He ◽  
Jingyun Wang ◽  
Dan Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Real Time ◽  
Fluorescent Dyes ◽  
Graphene Quantum Dots ◽  
Shell Nanoparticles ◽  
One Pot ◽  
Real Time Tracking

Fluorescence imaging offers a new approach to visualize real-time details on a cellular level in vitro and in vivo without radioactive damage. Poor light stability of organic fluorescent dyes makes long-term imaging difficult. Due to their outstanding optical properties and unique structural features, graphene quantum dots (GQDs) are promising in the field of imaging for real-time tracking in vivo. At present, GQDs are mainly loaded on the surface of nanoparticles. In this study, we developed an efficient and convenient one-pot method to load GQDs into nanoparticles, leading to longer metabolic processes in blood and increased delivery of GQDs to tumors. Optical-magneto ferroferric oxide@polypyrrole (Fe3O4@PPy) core-shell nanoparticles were chosen for their potential use in cancer therapy. The in vivo results demonstrated that by loading GQDs, it was possible to monitor the distribution and metabolism of nanoparticles. This study provided new insights into the application of GQDs in long-term in vivo real-time tracking.

Nontoxic Silicon Nanocrystals and Nanodiamonds as Substitution for Harmful Quantum Dots

2009 ◽  
Vol 1241 ◽  
Author(s):  
Anna Fucikova ◽  
Jan Valenta ◽  
Ivan Pelant ◽  
Vitezslav Brezina
Keyword(s):  
Quantum Dots ◽  
Chemical Composition ◽  
Silicon Nanocrystals ◽  
Nanocrystalline Silicon ◽  
Semiconductor Quantum Dots ◽  
In Vivo Studies ◽  
Long Term Stability

AbstractThe commercially available semiconductor quantum dots have been proven to be slightly to significantly toxic by recent publications depending on the chemical composition. We are developing new non-toxic fluorescent labels based on (i) nanocrystalline silicon, suitable for in vivo studies due to their biodegrability, and on (ii) nanodiamonds, intended mainly for in vitro use due to their long-term stability and nondegradilibity.

scholarly journals Oligodendrocytes support axonal transport and maintenance via exosome secretion

2019 ◽  
Author(s):  
Carsten Frühbeis ◽  
Wen Ping Kuo-Elsner ◽  
Christina Müller ◽  
Kerstin Barth ◽  
Leticia Peris ◽  
...  
Keyword(s):  
Axonal Transport ◽  
Glial Cells ◽  
Axonal Degeneration ◽  
Specific Gene ◽  
Neuronal Viability ◽  
Mouse Mutants ◽  
Gene Defects ◽  
Term Maintenance

AbstractNeurons extend long axons that require maintenance and are susceptible to degeneration. Long-term integrity of axons depends on intrinsic mechanisms including axonal transport and extrinsic support from adjacent glial cells. The mechanisms of support provided by myelinating oligodendrocytes to underlying axons are only partly understood. Oligodendrocytes release extracellular vesicles (EVs) with properties of exosomes, which upon delivery to neurons improve neuronal viability in vitro. Here, we show that oligodendroglial exosome secretion is impaired in two mouse mutants exhibiting secondary axonal degeneration due to oligodendrocyte-specific gene defects. Wildtype oligodendroglial exosomes support neurons by improving the metabolic state and promoting axonal transport in nutrient deprived neurons. Mutant oligodendrocytes release less exosomes that share a common signature of underrepresented proteins. Notably, mutant exosomes lack the ability to support nutrient deprived neurons and to promote axonal transport. Together, these findings indicate that glia to neuron exosome transfer promotes neuronal long-term maintenance by facilitating axonal transport, providing a novel mechanistic link between myelin diseases and secondary loss of axonal integrity.

scholarly journals Cellular Mechanisms Triggered by the Cotreatment of Resveratrol and Doxorubicin in Breast Cancer: A Translational In Vitro–In Silico Model

2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
José Eduardo Vargas ◽  
Renato Puga ◽  
Guido Lenz ◽  
Cristiano Trindade ◽  
Eduardo Filippi-Chiela
Keyword(s):  
Breast Cancer ◽  
In Silico ◽  
Molecular Mechanisms ◽  
Topological Analysis ◽  
Quantitative Model ◽  
Mcf7 Cells ◽  
Cellular Mechanisms ◽  
Autophagy Inhibition

Doxorubicin (Doxo) is the most effective chemotherapeutic agent for the treatment of breast cancer. However, resistance to Doxo is common. Adjuvant compounds capable of modulating mechanisms involved in Doxo resistance may potentiate the effectiveness of the drug. Resveratrol (Rsv) has been tested as an adjuvant in mammary malignancies. However, the cellular and molecular mechanisms underlying the effects of cotreatment with Doxo and Rsv in breast cancer are poorly understood. Here, we combined in vitro and in silico analysis to characterize these mechanisms. In vitro, we employed a clinically relevant experimental design consisting of acute (24 h) treatment followed by 15 days of analysis. Acute Rsv potentiated the long-lasting effect of Doxo through the induction of apoptosis and senescence. Cells that survived to the cotreatment triggered high levels of autophagy. Autophagy inhibition during its peak of activation but not concomitant with Doxo+Rsv increased the long-term toxicity of the cotreatment. To uncover key proteins potentially associated with in vitro effects, an in silico multistep strategy was implemented. Chemical-protein networks were predicted based on constitutive gene expression of MCF7 cells and interatomic data from breast cancer. Topological analysis, KM survival analysis, and a quantitative model based on the connectivity between apoptosis, senescence, and autophagy were performed. We found seven putative genes predicted to be modulated by Rsv in the context of Doxo treatment: CCND1, CDH1, ESR1, HSP90AA1, MAPK3, PTPN11, and RPS6KB1. Six out of these seven genes have been experimentally proven to be modulated by Rsv in cancer cells, with 4 of the 6 genes in MCF7 cells. In conclusion, acute Rsv potentiated the long-term toxicity of Doxo in breast cancer potentially through the modulation of genes and mechanisms involved in Doxo resistance. Rational autophagy inhibition potentiated the effects of Rsv+Doxo, a strategy that should be further tested in animal models.

scholarly journals Musa sp. paradisiaca Cultivar Gopi and Clonal fidelity Assessment using ISSR Marker

2019 ◽  
Vol 29 (2) ◽  
pp. 175-184
Author(s):  
Rabindra Kumar Sinha ◽  
Puja Rani Saha ◽  
Bibhash Nath ◽  
H. Reshmi Singha ◽  
Anath Bandhu Das ◽  
...  
Keyword(s):  
Shoot Multiplication ◽  
Shoot Elongation ◽  
High Rate ◽  
Clonal Fidelity ◽  
Musa Sp ◽  
Inter Simple Sequence Repeats ◽  
Fidelity Assessment ◽  
Simple Sequence

Attempt was made towards optimizing an in vitro shoot multiplication of banana cultivar Gopi with subsequent assessment of genetic stability. Experiments on enhanced shoot multiplication were conducted in MS fortified with BAP, Kn and 2-iP (4 mg/l) for a period of 8 weeks. Administration of exogenous root inducing growth regulator was eliminated to reduce culture investment and economy. Treatment with BAP supplemented medium proved to be optimum for shoot multiplication whereas 2-iP produced satisfactory results for shoot elongation. Long term incubation in all the treatments had been favorable for developing efficient root system. Hardening of in vitro grown plantlets showed high rate of survival (95%) upon transfer to potted soil. Assessment of clonal fidelity through inter simple sequence repeats (ISSR) analysis revealed 100% uniformity.

scholarly journals Nanodiamonds and silicon quantum dots: ultrastable and biocompatible luminescent nanoprobes for long-term bioimaging

2015 ◽  
Vol 44 (14) ◽  
pp. 4853-4921 ◽  
Author(s):  
M. Montalti ◽  
A. Cantelli ◽  
G. Battistelli
Keyword(s):  
Quantum Dots ◽  
Silicon Quantum Dots ◽  
Low Toxicity ◽  
Fluorescent Nanodiamonds

Ultra-stability and low-toxicity of silicon quantum dots and fluorescent nanodiamonds for long-termin vitroandin vivobioimaging are demonstrated.

The Use of Cultivated Land Retired From Active Rotation

2019 ◽  
Vol 5 (5) ◽  
pp. 153-159
Author(s):  
O. Karaseva ◽  
D. Ivanov ◽  
M. Rublyuk
Keyword(s):  
Vital Signs ◽  
Weather Conditions ◽  
Grain Legume ◽  
Botanical Composition ◽  
Russian Research Institute ◽  
Agrochemical Properties ◽  
Grass Stand ◽  
Term Monitoring ◽  
Observation Period

The paper describes trends in the evolution of vital signs of a long-lived five-component grass stand and agrochemical properties of soils under it at the reserve field of the agroecological testing ground of All-Russian Research Institute of Reclaimed Lands identified on the basis of long-term monitoring. The nature of changes in hay yield, botanical composition of herbs and agrochemical properties of the soil during aging of the stand is shown. It was revealed that the average yield of hay over the landfill during the observation period was less than 4 t/ha, its elevated values are observed on the slopes, especially noticeable in periods favorable under weather conditions. It has been shown that over the years of observations there has been a steady downward trend in the yield of the five-component grass mixture. The results of a statistical analysis of the dependence of hay yield on the botanical composition of the stand in different years are given. Regression analysis showed that in 2003–2005. there is a stage of noticeable influence of the spatial variability of the share of legumes on the hay yield (r ≈ 0.4), which was repeated in 2007–2008. (r = 0.58) and 2013–2014 (r ≈ 0.5). If we take into account the dynamics of the share of legumes in grass mixture, then we can say that the decline in productivity of grass and loss of crop quality is an expected fact due to objective processes of natural succession of agroecosystem on deposits and a decrease in soil fertility. The best terms of exploitation of multicomponent grain–legume grasses stand within the reserve fields are substantiated and measures for their introduction into agricultural rotation are determined. Proved the effectiveness of the measures for the reclamation of grass mixtures based on the culture and intermediate crops.

The metabolic responses of HepG2 cells to the exposure of mycotoxin deoxynivalenol

2016 ◽  
Vol 9 (4) ◽  
pp. 577-586 ◽  
Author(s):  
Y. Liu ◽  
R. Ran ◽  
C. Hu ◽  
B. Cui ◽  
Y. Xu ◽  
...  
Keyword(s):  
Hepg2 Cells ◽  
Redox Homeostasis ◽  
Short Term ◽  
Cellular Mechanisms ◽  
Metabolomics Data ◽  
Toxicological Effects ◽  
In Vitro Systems

As the number of reported deoxynivalenol (DON) contamination incidents increased steadily over the past decades, there has been a widespread interest in understanding the cellular mechanisms of the toxicological effects of DON using in vitro systems and omics technologies. The present investigation was conducted to understand the metabolomic changes in human hepatocellular carcinoma cells (HepG2) exposed to 10 μM DON for short term (4 h) and long term (12 h) periods, using a non-targeted metabolomics approach. Our results revealed a remarkable metabolic shift from short term to long term exposure to DON in HepG2 cells. Our metabolomics data also confirmed the role of DON induced oxidative stress in DON toxicity. Coupled with pattern recognition and pathway analysis, effects of DON on redox homeostasis, energy balance, lipid metabolism, and potential toxicological mechanisms were discussed, which would facilitate further studies on the risk assessment of the dietary mycotoxin DON.

scholarly journals Silicon Nanofluidic Membrane for Electrostatic Control of Drugs and Analytes Elution

Pharmaceutics ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 679 ◽  
Author(s):  
Nicola Di Trani ◽  
Antonia Silvestri ◽  
Yu Wang ◽  
Danilo Demarchi ◽  
Xuewu Liu ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Drug Delivery ◽  
Quantum Dots ◽  
Gate Dielectric ◽  
Membrane Surface ◽  
Drug Formulation ◽  
Micro Total Analysis Systems

Individualized long-term management of chronic pathologies remains an elusive goal despite recent progress in drug formulation and implantable devices. The lack of advanced systems for therapeutic administration that can be controlled and tailored based on patient needs precludes optimal management of pathologies, such as diabetes, hypertension, rheumatoid arthritis. Several triggered systems for drug delivery have been demonstrated. However, they mostly rely on continuous external stimuli, which hinder their application for long-term treatments. In this work, we investigated a silicon nanofluidic technology that incorporates a gate electrode and examined its ability to achieve reproducible control of drug release. Silicon carbide (SiC) was used to coat the membrane surface, including nanochannels, ensuring biocompatibility and chemical inertness for long-term stability for in vivo deployment. With the application of a small voltage (≤ 3 V DC) to the buried polysilicon electrode, we showed in vitro repeatable modulation of membrane permeability of two model analytes—methotrexate and quantum dots. Methotrexate is a first-line therapeutic approach for rheumatoid arthritis; quantum dots represent multi-functional nanoparticles with broad applicability from bio-labeling to targeted drug delivery. Importantly, SiC coating demonstrated optimal properties as a gate dielectric, which rendered our membrane relevant for multiple applications beyond drug delivery, such as lab on a chip and micro total analysis systems (µTAS).

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