scholarly journals Evaluation of Biological Toxicity of CdTe Quantum Dots in Trypanosoma cruzi

2020 ◽  
Vol 9 (12) ◽  
pp. e34391211274
Author(s):  
Graziella Santos Martins ◽  
Suzete Araújo Oliveira Gomes ◽  
Sônia Renaux Wanderley Louro ◽  
Eliane Wajnberg ◽  
Odivaldo Cambraia Alves ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Trypanosoma Cruzi ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Semiconductor Nanocrystals ◽  
Growth Curves ◽  
Ros Generation ◽  
Resonance Spectroscopy ◽  
Biological Toxicity

Luminescent semiconductor nanocrystals or quantum dots (QDs) emerge as important fluorescent probes for in vitro and in vivo Trypanosoma cruzi cells studies. However, to ensure applicability to living organisms, several tests still need to be done. Since several toxic events are caused by QDs, such as loss of mitochondrial membrane potential, ROS generation, DNA damage and cell death by autophagy. We performed a review of the literature on mechanisms of cellular uptake, internalization and citotoxicity of nanoparticles including our results about the evaluation of biological toxicity in T. cruzi. We evaluated the possible effects on parasite growth curves in a time - scale of control and incubated cells with different concentrations of CdTe – QDs (0.2; 2.0; 20 and 200µM) to determine the development cells changes. In addition, intracellular ROS were measured by Electron Paramagnetic Resonance Spectroscopy (EPR) technique. According our results, we can infer that the toxic effects of QDs in T. cruzi are dose-dependent and that high levels of ROS are involved in cellular toxicity promoted by higher concentrations of QDs. In summary, parasites labeled with low concentrations of nanoparticles are suitable and can be used as bioimaging tools for living parasites. However, more studies on QDs cytotoxicity need to be carried out.

In vitro Lipolysis as a Tool for the Establishment of IVIVC for Lipid-Based Drug Delivery Systems

2019 ◽  
Vol 16 (8) ◽  
pp. 688-697
Author(s):  
Ravinder Verma ◽  
Deepak Kaushik
Keyword(s):  
Drug Delivery ◽  
Ph Value ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Rapid Screening ◽  
Resonance Spectroscopy ◽  
Fed State ◽  
In Vitro Lipolysis ◽  
Ph Stat

: In vitro lipolysis has emerged as a powerful tool in the development of in vitro in vivo correlation for Lipid-based Drug Delivery System (LbDDS). In vitro lipolysis possesses the ability to mimic the assimilation of LbDDS in the human biological system. The digestion medium for in vitro lipolysis commonly contains an aqueous buffer media, bile salts, phospholipids and sodium chloride. The concentrations of these compounds are defined by the physiological conditions prevailing in the fasted or fed state. The pH of the medium is monitored by a pH-sensitive electrode connected to a computercontrolled pH-stat device capable of maintaining a predefined pH value via titration with sodium hydroxide. Copenhagen, Monash and Jerusalem are used as different models for in vitro lipolysis studies. The most common approach used in evaluating the kinetics of lipolysis of emulsion-based encapsulation systems is the pH-stat titration technique. This is widely used in both the nutritional and the pharmacological research fields as a rapid screening tool. Analytical tools for the assessment of in vitro lipolysis include HPLC, GC, HPTLC, SEM, Cryo TEM, Electron paramagnetic resonance spectroscopy, Raman spectroscopy and Nanoparticle Tracking Analysis (NTA) for the characterization of the lipids and colloidal phases after digestion of lipids. Various researches have been carried out for the establishment of IVIVC by using in vitro lipolysis models. The current publication also presents an updated review of various researches in the field of in vitro lipolysis.

scholarly journals Synthesis, Properties and Bioimaging Applications of Silver-Based Quantum Dots

2021 ◽  
Vol 22 (22) ◽  
pp. 12202
Author(s):  
Mariya Borovaya ◽  
Inna Horiunova ◽  
Svitlana Plokhovska ◽  
Nadia Pushkarova ◽  
Yaroslav Blume ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Near Infrared ◽  
Semiconductor Nanocrystals ◽  
Current Status ◽  
Synthesis Properties ◽  
Semiconductor Nanomaterials ◽  
Electrooptical Properties ◽  
Basic Features

Ag-based quantum dots (QDs) are semiconductor nanomaterials with exclusive electrooptical properties ideally adaptable for various biotechnological, chemical, and medical applications. Silver-based semiconductor nanocrystals have developed rapidly over the past decades. They have become a promising luminescent functional material for in vivo and in vitro fluorescent studies due to their ability to emit at the near-infrared (NIR) wavelength. In this review, we discuss the basic features of Ag-based QDs, the current status of classic (chemical) and novel methods (“green” synthesis) used to produce these QDs. Additionally, the advantages of using such organisms as bacteria, actinomycetes, fungi, algae, and plants for silver-based QDs biosynthesis have been discussed. The application of silver-based QDs as fluorophores for bioimaging application due to their fluorescence intensity, high quantum yield, fluorescent stability, and resistance to photobleaching has also been reviewed.

scholarly journals Nitric oxide interactions with cobalamins: biochemical and functional consequences

Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1857-1864 ◽  
Author(s):  
M Brouwer ◽  
W Chamulitrat ◽  
G Ferruzzi ◽  
DL Sauls ◽  
JB Weinberg
Keyword(s):  
Nitric Oxide ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
No Formation ◽  
Iron Nitrosyl ◽  
Wide Range ◽  
Functional Consequences

Abstract Nitric oxide (NO) is a paramagnetic gas that has been implicated in a wide range of biologic functions. The common pathway to evoke the functional response frequently involves the formation of an iron- nitrosyl complex in a target (heme) protein. In this study, we report on the interactions between NO and cobalt-containing vitamin B12 derivatives. Absorption spectroscopy showed that of the four Co(III) derivatives (cyanocobalamin [CN-Cbl], aquocobalamin [H2O-Cbl], adenosylcobalamin [Ado-Cbl], and methylcobalamin [MeCbl]), only the H2O- Cbl combined with NO. In addition, electron paramagnetic resonance spectroscopy of H2O-Cbl preparations showed the presence of a small amount of Cob-(II)alamin that was capable of combining with NO. The Co(III)-NO complex was very stable, but could transfer its NO moiety to hemoglobin (Hb). The transfer was accompanied by a reduction of the Co(III) to Co(II), indicating that NO+ (nitrosonium) was the leaving group. In accordance with this, the NO did not combine with the Hb Fe(II)-heme, but most likely with the Hb cysteine-thiolate. Similarly, the Co(III)-NO complex was capable of transferring its NO to glutathione. Ado-Cbl and Me-Cbl were susceptible to photolysis, but CN- Cbl and H2O-Cbl were not. The homolytic cleavage of the Co(III)-Ado or Co(III)-Me bond resulted in the reduction of the metal. When photolysis was performed in the presence of NO, formation of NO-Co(II) was observed. Co(II)-nitrosyl oxidized slowly to form Co(III)-nitrosyl. The capability of aquocobalamin to combine with NO had functional consequences. We found that nitrosylcobalamin had diminished ability to serve as a cofactor for the enzyme methionine synthase, and that aquocobalamin could quench NO-mediated inhibition of cell proliferation. Our in vitro studies therefore suggest that interactions between NO and cobalamins may have important consequences in vivo.

Baicalein attenuates oxidant stress in cardiomyocytes

2002 ◽  
Vol 282 (3) ◽  
pp. H999-H1006 ◽  
Author(s):  
Zuo-Hui Shao ◽  
Terry L. Vanden Hoek ◽  
Yimin Qin ◽  
Lance B. Becker ◽  
Paul T. Schumacker ◽  
...  
Keyword(s):  
Cell Death ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Ischemia Reperfusion ◽  
Oxidant Stress ◽  
Complex Iii ◽  
Ros Generation ◽  
Resonance Spectroscopy ◽  
Iodide Uptake ◽  
Simulated Ischemia

Flavonoids within Scutellaria baicalensis may be potent antioxidants on the basis of our studies of S. baicalensis extract. To further this work, we studied the antioxidative effects of baicalein, a flavonoid component of S. baicalensis, in a chick cardiomyocyte model of reactive oxygen species (ROS) generation during hypoxia, simulated ischemia-reperfusion, or mitochondrial complex III inhibition with antimycin A. Oxidant stress was measured by oxidation of the intracellular probes 2′,7′-dichlorofluorescin diacetate and dihydroethidium. Viability was assessed by propidium iodide uptake. Baicalein attenuated oxidant stress during all conditions studied and acted within minutes of treatment. For example, baicalein given only at reperfusion dose dependently attenuated the ROS burst at 5 min after 1 h of simulated ischemia. It also decreased subsequent cell death at 3 h of reperfusion from 52.3 ± 2.5% in untreated cells to 29.4 ± 3.0% (with return of contractions; P < 0.001). In vitro studies using electron paramagnetic resonance spectroscopy with the spin trap 5-methoxycarbonyl-5-methyl-1-pyrroline- N-oxide revealed that baicalein scavenges superoxide but does not mimic the effects of superoxide dismutase. We conclude that baicalein can scavenge ROS generation in cardiomyocytes and that it protects against cell death in an ischemia-reperfusion model when given only at reperfusion.

scholarly journals A Second [2Fe-2S] Ferredoxin from Sphingomonas sp. Strain RW1 Can Function as an Electron Donor for the Dioxin Dioxygenase

2000 ◽  
Vol 182 (8) ◽  
pp. 2238-2244 ◽  
Author(s):  
Jean Armengaud ◽  
Jacques Gaillard ◽  
Kenneth N. Timmis
Keyword(s):  
Electron Donor ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
In Vitro Assays ◽  
Resonance Spectroscopy ◽  
Hydrogen Electrode ◽  
Visible Absorption ◽  
Paramagnetic Resonance ◽  
Reading Frame

ABSTRACT The first step in the degradation of dibenzofuran and dibenzo-p-dioxin by Sphingomonas sp. strain RW1 is carried out by dioxin dioxygenase (DxnA1A2), a ring-dihydroxylating enzyme. An open reading frame (fdx3) that could potentially specify a new ferredoxin has been identified downstream ofdxnA1A2, a two-cistron gene (J. Armengaud, B. Happe, and K. N. Timmis, J. Bacteriol. 180:3954–3966, 1998). In the present study, we report a biochemical analysis of Fdx3 produced inEscherichia coli. This third ferredoxin thus far identified in Sphingomonas sp. strain RW1 contained a putidaredoxin-type [2Fe-2S] cluster which was characterized by UV-visible absorption spectrophotometry and electron paramagnetic resonance spectroscopy. The midpoint redox potential of this ferredoxin (E′0 = −247 ± 10 mV versus normal hydrogen electrode at pH 8.0) is similar to that exhibited by Fdx1 (−245 mV), a homologous ferredoxin previously characterized inSphingomonas sp. strain RW1. In in vitro assays, Fdx3 can be reduced by RedA2 (a reductase similar to class I cytochrome P-450 reductases), previously isolated from Sphingomonas sp. strain RW1. RedA2 exhibits a Km value of 3.2 ± 0.3 μM for Fdx3. In vivo coexpression of fdx3and redA2 with dxnA1A2 confirmed that Fdx3 can serve as an electron donor for the dioxin dioxygenase.

In vitro and in vivo documentation of quantum dots labeled Trypanosoma cruzi–Rhodnius prolixus interaction using confocal microscopy

2009 ◽  
Vol 106 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Denise Feder ◽  
Suzete A. O. Gomes ◽  
André A. de Thomaz ◽  
Diogo B. Almeida ◽  
Wagner M. Faustino ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Confocal Microscopy ◽  
Trypanosoma Cruzi ◽  
Rhodnius Prolixus

scholarly journals Nitric oxide interactions with cobalamins: biochemical and functional consequences

Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1857-1864
Author(s):  
M Brouwer ◽  
W Chamulitrat ◽  
G Ferruzzi ◽  
DL Sauls ◽  
JB Weinberg
Keyword(s):  
Nitric Oxide ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
No Formation ◽  
Iron Nitrosyl ◽  
Wide Range ◽  
Functional Consequences

Nitric oxide (NO) is a paramagnetic gas that has been implicated in a wide range of biologic functions. The common pathway to evoke the functional response frequently involves the formation of an iron- nitrosyl complex in a target (heme) protein. In this study, we report on the interactions between NO and cobalt-containing vitamin B12 derivatives. Absorption spectroscopy showed that of the four Co(III) derivatives (cyanocobalamin [CN-Cbl], aquocobalamin [H2O-Cbl], adenosylcobalamin [Ado-Cbl], and methylcobalamin [MeCbl]), only the H2O- Cbl combined with NO. In addition, electron paramagnetic resonance spectroscopy of H2O-Cbl preparations showed the presence of a small amount of Cob-(II)alamin that was capable of combining with NO. The Co(III)-NO complex was very stable, but could transfer its NO moiety to hemoglobin (Hb). The transfer was accompanied by a reduction of the Co(III) to Co(II), indicating that NO+ (nitrosonium) was the leaving group. In accordance with this, the NO did not combine with the Hb Fe(II)-heme, but most likely with the Hb cysteine-thiolate. Similarly, the Co(III)-NO complex was capable of transferring its NO to glutathione. Ado-Cbl and Me-Cbl were susceptible to photolysis, but CN- Cbl and H2O-Cbl were not. The homolytic cleavage of the Co(III)-Ado or Co(III)-Me bond resulted in the reduction of the metal. When photolysis was performed in the presence of NO, formation of NO-Co(II) was observed. Co(II)-nitrosyl oxidized slowly to form Co(III)-nitrosyl. The capability of aquocobalamin to combine with NO had functional consequences. We found that nitrosylcobalamin had diminished ability to serve as a cofactor for the enzyme methionine synthase, and that aquocobalamin could quench NO-mediated inhibition of cell proliferation. Our in vitro studies therefore suggest that interactions between NO and cobalamins may have important consequences in vivo.

Unusual dimeric flavonoids from Arrabidaea brachypoda with very significant in vitro and in vivo anti-Trypanosoma cruzi activity

Planta Medica ◽  
2014 ◽  
Vol 80 (16) ◽  
Author(s):  
C Quitino-da-Rocha ◽  
E Ferreira-Queiroz ◽  
C Santana-Meira ◽  
DR Magalhães-Moreira ◽  
M Botelho-Pereira-Soares ◽  
...  
Keyword(s):  
Trypanosoma Cruzi

scholarly journals Fe3O4@Pt nanoparticles to enable combinational electrodynamic/chemodynamic therapy

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Tong Chen ◽  
Qiang Chu ◽  
Mengyang Li ◽  
Gaorong Han ◽  
Xiang Li
Keyword(s):  
Fenton Reaction ◽  
Pt Nanoparticles ◽  
Therapeutic Modality ◽  
Ros Generation ◽  
Tumor Treatment ◽  
Superior Efficacy ◽  
Platinum Nanocrystals ◽  
First Time

AbstractElectrodynamic therapy (EDT) has recently emerged as a potential external field responsive approach for tumor treatment. While it presents a number of clear superiorities, EDT inherits the intrinsic challenges of current reactive oxygen species (ROS) based therapeutic treatments owing to the complex tumor microenvironment, including glutathione (GSH) overexpression, acidity and others. Herein for the first time, iron oxide nanoparticles are decorated using platinum nanocrystals (Fe3O4@Pt NPs) to integrate the current EDT with chemodynamic phenomenon and GSH depletion. Fe3O4@Pt NPs can effectively induce ROS generation based on the catalytic reaction on the surface of Pt nanoparticles triggered by electric field (E), and meanwhile it may catalyze intracellular H2O2 into ROS via Fenton reaction. In addition, Fe3+ ions released from Fe3O4@Pt NPs under the acidic condition in tumor cells consume GSH in a rapid fashion, inhibiting ROS clearance to enhance its antitumor efficacy. As a result, considerable in vitro and in vivo tumor inhibition phenomena are observed. This study has demonstrated an alternative concept of combinational therapeutic modality with superior efficacy.

scholarly journals Synthesis and Characterization of Polyvinylpyrrolidone-Modified ZnO Quantum Dots and Their In Vitro Photodynamic Tumor Suppressive Action

2021 ◽  
Vol 22 (15) ◽  
pp. 8106
Author(s):  
Tianming Song ◽  
Yawei Qu ◽  
Zhe Ren ◽  
Shuang Yu ◽  
Mingjian Sun ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Photodynamic Therapy ◽  
Inhibitory Effect ◽  
Therapeutic Effects ◽  
In Vivo Experiments ◽  
Potential Applications ◽  
Zno Quantum Dots ◽  
Zno Qds

Despite the numerous available treatments for cancer, many patients succumb to side effects and reoccurrence. Zinc oxide (ZnO) quantum dots (QDs) are inexpensive inorganic nanomaterials with potential applications in photodynamic therapy. To verify the photoluminescence of ZnO QDs and determine their inhibitory effect on tumors, we synthesized and characterized ZnO QDs modified with polyvinylpyrrolidone. The photoluminescent properties and reactive oxygen species levels of these ZnO/PVP QDs were also measured. Finally, in vitro and in vivo experiments were performed to test their photodynamic therapeutic effects in SW480 cancer cells and female nude mice. Our results indicate that the ZnO QDs had good photoluminescence and exerted an obvious inhibitory effect on SW480 tumor cells. These findings illustrate the potential applications of ZnO QDs in the fields of photoluminescence and photodynamic therapy.

Sign in / Sign up

Export Citation Format

Share Document