Efficiency of Cationic Rosette Nanotubes for siRNA Delivery

2011 ◽  
Vol 1316 ◽  
Author(s):  
Aws Alshamsan ◽  
Mounir EL Bakkari ◽  
Hicham Fenniri
Keyword(s):  
Binding Capacity ◽  
Sirna Delivery ◽  
Supramolecular Assembly ◽  
Agarose Gel ◽  
Cell Toxicity ◽  
Rosette Nanotubes ◽  
Gel Retardation Assay ◽  
Lysine Residues ◽  
Spherical Structures ◽  
First Time

ABSTRACTCationic rosette nanotubes (RNTs) were generated by functionalization of selfcomplementary twin guanine-cytosine (G^C) motifs with up to 15 L-lysine residues (Kn.T, n = 1–15). siRNA binding capacity was determined by gel retardation assay on agarose gel. Up to K5.T, siRNA complexation was a function of oligolysine-chain length and mole ratio of Kn.T. At higher Kn.T, local cationic density employed by supramolecular assembly emerged as a contributor to siRNA complexation. We have shown that no effective siRNA binding was achieved with equivalent mole ratios of corresponding oligolysine peptides (not conjugated to the G∧C motif). With K12.T, siRNA complexation gave spherical structures in the range of 200 nm, which was internalized and retained by human cell lines without noticeable cytotoxicity. In this report, we demonstrate for the first time the capacity of the RNTs as siRNA carriers that can be tailored to achieve maximum siRNA loading efficiency without carrier-associated cell toxicity. We anticipate these cationic RNTs to be effective in the delivery of biologicallyfunctional siRNA.

scholarly journals The synergistic interference effect of silica nanoparticles concentration and the wavelength of ELISA on the colorimetric assay of cell toxicity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fariba Abbasi ◽  
Hassan Hashemi ◽  
Mohammad Reza Samaei ◽  
Amir SavarDashtaki ◽  
Abooalfazl Azhdarpoor ◽  
...  
Keyword(s):  
Mtt Assay ◽  
Interference Effect ◽  
Polynomial Regression ◽  
Colorimetric Assay ◽  
Synergistic Effects ◽  
Cell Toxicity ◽  
Diphenyltetrazolium Bromide ◽  
Nanoparticles Concentration ◽  
Artificial Neural Network Ann ◽  
First Time

AbstractThe 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay is the most common method for the determination of cell toxicity, but some factors limit the sensitivity of this method, such as pH. Less attention had been paid to the interference effect of optical and plasmonic properties of SiO2 nanoparticles (NPs) in the wavelength range assigned to MTT. This study investigated the synergistic interference effect of SiO2 NPs and wavelength on MTT assay for the first time. The examined variables included the type of SiO2 NPs concentrations (1, 10, and 100 mM) and different wavelengths (470, 490, 520, and 570 nm). The results showed that optical density (OD) increased (p < 0.05) when wavelength and the concentration of crystalline SiO2 NPs increased. So, the maximum OD at 10 and 100 mM were attributed to crystalline SiO2 NPs (p < 0.05) due to the functional group, whereas it was related to amorphous at 1 mM (p > 0.05). According to polynomial regression modeling (PRM), the maximum interference effect was predicted at crystalline SiO2 NPs and wavelength > 550 nm. Besides, the synergistic effects of SiO2 NPs, wavelength, and concentration of NPs had been a good fitting with first-order PRM. Thus, the concentration of SiO2 NPs had a confounder factor in colorimetric for MTT assay. The best artificial neural network (ANN) structure was related to the 3:7:1 network (Rall = 0.936, MSE = 0.0006, MAPE = 0.063). The correlation between the actual and predicted data was 0.88. As SiO2 NPs presence is an interfering factor in MTT assay concerning wavelength, it is suggested wavelength use with minimum confounding effect for MTT assay.

Helical Rosette Nanotubes as a Potentially More Effective Orthopaedic Implant Material

2004 ◽  
Vol 845 ◽  
Author(s):  
Ai Lin Chun ◽  
Hicham Fenniri ◽  
Thomas J. Webster
Keyword(s):  
Tissue Engineering ◽  
Surface Roughness ◽  
Bone Cells ◽  
In Vitro Study ◽  
Orthopaedic Implant ◽  
Rosette Nanotubes ◽  
Osteoblast Adhesion ◽  
Organic Nanotubes ◽  
First Time

ABSTRACTOrganic nanotubes called helical rosette nanotubes (HRN) have been synthesized in this study for bone tissue engineering applications. They possess intriguing properties for various bionanotechnology applications since they can be designed to mimic the nanostructured constituent components in bone such as collagen fibers and hydroxyapatite (Ca5(PO4)3(OH)) which bone cells are naturally accustomed to interacting with. This is in contrast to currently used orthopaedic materials such as titanium which do not possess desirable nanometer surface roughness. The objective of this in vitro study was to determine bone-forming cell (osteoblasts) interactions on titanium coated with HRNs. Results of this study showed for the first time increased osteoblast adhesion on titanium coated with HRNs compared to those not coated with HRNs. In this manner, this study provided evidence that HRNs should be further considered for orthopaedic applications.

scholarly journals Cyclic AMP-dependent Protein Lysine Acylation in Mycobacteria Regulates Fatty Acid and Propionate Metabolism

2013 ◽  
Vol 288 (20) ◽  
pp. 14114-14124 ◽  
Author(s):  
Subhalaxmi Nambi ◽  
Kallol Gupta ◽  
Moitrayee Bhattacharyya ◽  
Parvathy Ramakrishnan ◽  
Vaishnavi Ravikumar ◽  
...  
Keyword(s):  
Critical Role ◽  
Fatty Acyl ◽  
Intracellular Camp ◽  
Dependent Manner ◽  
Multiple Substrates ◽  
Propionate Metabolism ◽  
Lysine Residues ◽  
Dependent Protein ◽  
First Time ◽  
Camp Levels

Acetylation of lysine residues is a posttranslational modification that is used by both eukaryotes and prokaryotes to regulate a variety of biological processes. Here we identify multiple substrates for the cAMP-dependent protein lysine acetyltransferase from Mycobacterium tuberculosis (KATmt). We demonstrate that a catalytically important lysine residue in a number of FadD (fatty acyl CoA synthetase) enzymes is acetylated by KATmt in a cAMP-dependent manner and that acetylation inhibits the activity of FadD enzymes. A sirtuin-like enzyme can deacetylate multiple FadDs, thus completing the regulatory cycle. Using a strain deleted for the KATmt ortholog in Mycobacterium bovis Bacillus Calmette-Guérin (BCG), we show for the first time that acetylation is dependent on intracellular cAMP levels. KATmt can utilize propionyl CoA as a substrate and, therefore, plays a critical role in alleviating propionyl CoA toxicity in mycobacteria by inactivating acyl CoA synthetase (ACS). The precision by which mycobacteria can regulate the metabolism of fatty acids in a cAMP-dependent manner appears to be unparalleled in other biological organisms and is ideally suited to adapt to the complex environment that pathogenic mycobacteria experience in the host.

scholarly journals Flavonoids from Chionanthus retusus (Oleaceae) Flowers and Their Protective Effects against Glutamate-Induced Cell Toxicity in HT22 Cells

2019 ◽  
Vol 20 (14) ◽  
pp. 3517 ◽  
Author(s):  
Yeong-Geun Lee ◽  
Hwan Lee ◽  
Jae-Woo Jung ◽  
Kyeong-Hwa Seo ◽  
Dae Young Lee ◽  
...  
Keyword(s):  
Protein Expression ◽  
Cell Damage ◽  
Neuroprotective Activity ◽  
Raw 264.7 Cells ◽  
No Production ◽  
Protective Effects ◽  
Cell Toxicity ◽  
Ht22 Cells ◽  
Etoac Fraction ◽  
First Time

The dried flowers of Chionanthus retusus were extracted with 80% MeOH, and the concentrate was divided into EtOAc, n-BuOH, and H2O fractions. Repeated SiO2, octadecyl SiO2 (ODS), and Sephadex LH-20 column chromatography of the EtOAc fraction led to the isolation of four flavonols (1–4), three flavones (5–7), four flavanonols (8–11), and one flavanone (12), which were identified based on extensive analysis of various spectroscopic data. Flavonoids 4–6 and 8–11 were isolated from the flowers of C. retusus for the first time in this study. Flavonoids 1, 2, 5, 6, 8, and 10–12 significantly inhibited NO production in RAW 264.7 cells stimulated by lipopolysaccharide (LPS) and glutamate-induced cell toxicity and effectively increased HO-1 protein expression in mouse hippocampal HT22 cells. Flavonoids with significant neuroprotective activity were also found to recover oxidative-stress-induced cell damage by increasing HO-1 protein expression. This article demonstrates that flavonoids from C. retusus flowers have significant potential as therapeutic materials in inflammation and neurodisease.

Neurotoxicity of Dental Amalgam is Mediated by Zinc

2003 ◽  
Vol 82 (3) ◽  
pp. 243-246 ◽  
Author(s):  
D Lobner ◽  
M Asrari
Keyword(s):  
Cortical Cell ◽  
Dental Amalgam ◽  
The Body ◽  
Neuronal Cultures ◽  
Cell Toxicity ◽  
Mercury Toxicity ◽  
Metal Chelator ◽  
Cortical Cell Cultures ◽  
Zinc Levels ◽  
First Time

The use of dental amalgam is controversial largely because it contains mercury. We tested whether amalgam caused toxicity in neuronal cultures and whether that toxicity was caused by mercury. In this study, we used cortical cell cultures to show for the first time that amalgam causes nerve cell toxicity in culture. However, the toxicity was not blocked by the mercury chelator, 2,3-dimercaptopropane-1-sulphonate (DMPS), but was blocked by the metal chelator, calcium disodium ethylenediaminetetraacetate (CaEDTA). DMPS was an effective mercury chelator in this system, since it blocked mercury toxicity. Of the components that comprise amalgam (mercury, zinc, tin, copper, and silver), only zinc neurotoxicity was blocked by CaEDTA. These results indicate that amalgam is toxic to nerve cells in culture by releasing zinc. While zinc is known to be neurotoxic, ingestion of zinc is not a major concern because zinc levels in the body are tightly regulated.

scholarly journals Plasminogen Acquisition and Activation at the Surface of Leptospira Species Lead to Fibronectin Degradation

2009 ◽  
Vol 77 (9) ◽  
pp. 4092-4101 ◽  
Author(s):  
Monica L. Vieira ◽  
Silvio A. Vasconcellos ◽  
Amane P. Gonçales ◽  
Zenaide M. de Morais ◽  
Ana L. T. O. Nascimento
Keyword(s):  
Aminocaproic Acid ◽  
Cellular Growth ◽  
Activation System ◽  
Lysine Residues ◽  
Etiological Agents ◽  
Low Passage ◽  
First Time ◽  
Dose Dependent ◽  
Leptospira Species

ABSTRACT Pathogenic Leptospira species are the etiological agents of leptospirosis, a widespread disease of human and veterinary concern. In this study, we report that Leptospira species are capable of binding plasminogen (PLG) in vitro. The binding to the leptospiral surface was demonstrated by indirect immunofluorescence confocal microscopy with living bacteria. The PLG binding to the bacteria seems to occur via lysine residues because the ligation is inhibited by addition of the lysine analog 6-aminocaproic acid. Exogenously provided urokinase-type PLG activator (uPA) converts surface-bound PLG into enzymatically active plasmin, as evaluated by the reaction with the chromogenic plasmin substrate d-Val-Leu-Lys 4-nitroanilide dihydrochloridein. The PLG activation system on the surface of Leptospira is PLG dose dependent and does not cause injury to the organism, as cellular growth in culture was not impaired. The generation of active plasmin within Leptospira was observed with several nonvirulent high-passage strains and with the nonpathogenic saprophytic organism Leptospira biflexa. Statistically significant higher activation of plasmin was detected with a low-passage infectious strain of Leptospira. Plasmin-coated virulent Leptospira interrogans bacteria were capable of degrading purified extracellular matrix fibronectin. The breakdown of fibronectin was not observed with untreated bacteria. Our data provide for the first time in vitro evidence for the generation of active plasmin on the surface of Leptospira, a step that may contribute to leptospiral invasiveness.

scholarly journals Construction of a Novel Chimeric Dextransucrase Fused to the Carbohydrate-Binding Module CBM2a

2021 ◽  
Author(s):  
Reinaldo Fraga Vidal ◽  
Roberto Carlos Aristicas Ribalta ◽  
Lisandra Teresa Martínez Valdés ◽  
Meinardo Lafargue Gámez ◽  
Amanda Montes Alvarez ◽  
...  
Keyword(s):  
Binding Capacity ◽  
Structural Characteristics ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Molecular Weights ◽  
Isolation And Characterization ◽  
The Subject ◽  
Encoding Gene ◽  
First Time

The lactic acid bacteria (LAB) have great potential to produce homoexopolysaccharides (HoPS), have been the subject of extensive research efforts, given their health benefits and physicochemical properties. The HoPS functional properties are determined by structural characteristics of varied molecular weights, types of glycosidic linkages, degrees of branching and chemical composition. The dextransucrases (DSases) are responsible of the synthesis of a kind of HoPS (dextran polymers), which are among the first biopolymers produced at industrial scale with applications in medicine and biotechnology. The concept of glycodiversification opens additional applications for DSases. In that sense the design and characterization of new DSases is of prime importance. Previously, we described the isolation and characterization of a novel extracellular dextransucrase (DSR-F) encoding gene. In this study, from DSR-F, we design a novel chimeric dextransucrase DSR-F-∆SP-∆GBD-CBM2a, where DSR-F-∆SP-∆GBD is fused to the carbohydrate-binding module (CBM2a) of the &beta;-1-4 exoglucanase/xylanase Cex (Xyn10A) of Cellulomonas fimi ATCC 484. This dextransucrase variant is active and without alteration in its specificity. The DSR-F-∆SP-∆GBD-CBM2a is purified by cellulose affinity chromatography for the very first time. Our results indicate that new hybrids and chimeric DSases with novel binding capacity to cellulose can be designed to obtain glyco-biocatalysts from renewable lignocellulosic materials.

scholarly journals Enhancing Antibodies’ Binding Capacity through Oriented Functionalization of Plasmonic Surfaces

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2620
Author(s):  
Maria Laura Coluccio ◽  
Fabiana Grillo ◽  
Valentina Onesto ◽  
Virginia Garo ◽  
Cinzia Scala ◽  
...  
Keyword(s):  
Silicon Surface ◽  
Binding Capacity ◽  
Protein A ◽  
Antigen Binding ◽  
Crucial Importance ◽  
Enhanced Fluorescence ◽  
Immobilized Antibodies ◽  
Research Fields ◽  
Fragment Antigen Binding ◽  
First Time

Protein A has long been used in different research fields due to its ability to specifically recognize immunoglobulins (Ig). The protein derived from Staphylococcus aureus binds Ig through the Fc region of the antibody, showing its strongest binding in immunoglobulin G (IgG), making it the most used protein in its purification and detection. The research presented here integrates, for the first time, protein A to a silicon surface patterned with gold nanoparticles for the oriented binding of IgG. The signal detection is conveyed through a metal enhanced fluorescence (MEF) system. Orienting immunoglobulins allows the exposition of the fragment antigen-binding (Fab) region for the binding to its antigen, substantially increasing the binding capacity per antibody immobilized. Antibodies orientation is of crucial importance in many diagnostics devices, particularly when either component is in limited quantities.

scholarly journals Influence of powder from tuber topinambur on the consumer properties of venison cutlets in storage

2020 ◽  
Vol 203 ◽  
pp. 04001
Author(s):  
Inessa Zaсhesova ◽  
Stanislav Kolobov ◽  
Natalia Shagaeva
Keyword(s):  
Heat Treatment ◽  
Lipid Oxidation ◽  
Binding Capacity ◽  
Jerusalem Artichoke ◽  
High Quality ◽  
Water Binding ◽  
Mechanical Methods ◽  
Subsequent Storage ◽  
First Time

For the first time, studies were conducted on changes in the consumer properties of cutlets with powder from Jerusalem artichoke tubers during storage. In solving these problems, generally accepted special organoleptic, physicochemical, microbiological, structural and mechanical methods for studying the properties of finished products were used. It has been established that venison cutlets with Jerusalem artichoke tubers powder are characterized by greater stability of consumer properties compared to cutlets without Jerusalem artichoke tubers powder. During freezing and subsequent storage of cutlets, a decrease in water binding capacity and an increase in losses during heat treatment were noted. It should be noted that these changes were less pronounced in cutlets with powder from Jerusalem artichoke tubers, compared with cutlets without powder from Jerusalem artichoke tubers. It was found that cutlets with powder from Jerusalem artichoke tubers produced with powder from Jerusalem artichoke tubers showed a lower level of lipid oxidation compared to cutlets without powder from Jerusalem artichoke tubers. The results of the tasting assessment confirmed the high quality of venison cutlets with Jerusalem artichoke tubers powder.

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