Effect of polypyridine copper complex [Cu(dppz)(l-Ser)]NO3·H2O on the stabilization of triplex DNA based on gold-nanoparticles

2015 ◽  
Vol 7 (8) ◽  
pp. 3425-3430
Author(s):  
Wu Chengke ◽  
An Xiaoyu ◽  
Yue yuanyuan Yue yuanyuan ◽  
Feng Suling ◽  
Niu Xiaoqing
Keyword(s):  
Gold Nanoparticles ◽  
Copper Complex ◽  
Triplex Dna ◽  
Alkaline Environment ◽  
Triplex Structure ◽  
The Stability

[Cu(dppz)(l-Ser)]NO3·H2O, as an intercalator, improved the stability of the triplex structure under a weak alkaline environment.

scholarly journals Surface Adsorption of the Alpha-Emitter Astatine-211 to Gold Nanoparticles Is Stable In Vivo and Potentially Useful in Radionuclide Therapy

2021 ◽  
Vol 2 (4) ◽  
pp. 196-207
Author(s):  
Emanuel Sporer ◽  
Christian B. M. Poulie ◽  
Sture Lindegren ◽  
Emma Aneheim ◽  
Holger Jensen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Surface Adsorption ◽  
Radiochemical Yield ◽  
Gold Surface ◽  
Mouse Serum ◽  
Control Group ◽  
Alpha Emitter ◽  
Before And After ◽  
The Stability

Targeted α-therapy (TAT) can eradicate tumor metastases while limiting overall toxicity. One of the most promising α-particle emitters is astatine-211 (211At). However, 211At-carbon bonds are notoriously unstable in vivo and no chelators are available. This hampers its adoption in TAT. In this study, the stability of 211At on the surface of gold nanoparticles (AuNPs) was investigated. The employed AuNPs had sizes in the 25–50 nm range. Radiolabeling by non-specific surface-adsorption in >99% radiochemical yield was achieved by mixing 211At and AuNPs both before and after polyethylene glycol (PEG) coating. The resulting 211At-AuNPs were first challenged by harsh oxidation with sodium hypochlorite, removing roughly 50% of the attached 211At. Second, incubation in mouse serum followed by a customized stability test, showed a stability of >95% after 4 h in serum. This high stability was further confirmed in an in vivo study, with comparison to a control group of free 211At. The AuNP-associated 211At showed low uptake in stomach and thyroid, which are hallmark organs of uptake of free 211At, combined with long circulation and high liver and spleen uptake, consistent with nanoparticle biodistribution. These results support that gold surface-adsorbed 211At has high biological stability and is a potentially useful delivery system in TAT.

Stability of carbon monoxide oxidation process on gold nanoparticles

2020 ◽  
Vol 8 (1) ◽  
pp. 116-124
Author(s):  
P. P. Kostrobij ◽  
◽  
I. A. Ryzha ◽  
Keyword(s):  
Carbon Monoxide ◽  
Gold Nanoparticles ◽  
Reaction Mechanisms ◽  
Structural Changes ◽  
Oxidation Process ◽  
Lyapunov Method ◽  
Catalyst Surface ◽  
Carbon Monoxide Oxidation ◽  
One Step ◽  
The Stability

The stability conditions for mathematical models of carbon monoxide oxidation on the surface of gold nanoparticles are investigated. The cases of reaction mechanisms of one-step and step-by-step transformation of reagents are consecutively considered. Using the stability analysis by Lyapunov method, it is shown that models which take into account the possibility of structural changes of the catalyst surface can predict the occurrence of oscillatory mode in the system as a result of Hopf instability.

scholarly journals SYNTHESIS AND STABILITY OF RESVERATROL-CONJUGATED GOLD NANOPARTICLES MODIFIED WITH POLYETHYLENE GLYCOL

2020 ◽  
pp. 230-236
Author(s):  
RADITYA ISWANDANA ◽  
RICHA NURSELVIANA ◽  
SUTRIYO SUTRIYO
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Zeta Potential ◽  
High Performance ◽  
Entrapment Efficiency ◽  
Test Results ◽  
Novel Method ◽  
The Stability ◽  
Phosphate Buffered Saline

Objective: Gold nanoparticles (AuNPs) are highly useful for drug delivery, but their application is limited by their stability as they readily aggregate.This issue can be prevented by adding a stabilizing agent such as resveratrol (RSV), which is a polyphenol derived from plants, that is used to preventcancer. Therefore, we propose a novel method to prepare stable RSV-conjugated nanoparticles modified with polyethylene glycol (RSV-AuNP-PEG).Methods: In the first step, the Turkevich method was used to synthesize the AuNPs. Then, PEG was added as stabilizer agent and conjugated with RSV.The synthesized conjugates were characterized using ultraviolet-visible spectrophotometry, Fourier transform infrared spectroscopy, particle sizeanalysis, and high-performance liquid chromatography.Results: The obtained RSV-AuNP-PEG had a particle size of 83.93 nm with a polydispersity index (PDI) of 0.562 and formed a translucent purple-redfluid in solution. The zeta potential was −22.9 mV, and the highest entrapment efficiency was 75.86±0.66%. For comparison, the RSV-AuNP solutionwas purple and turbid, the particle size was 51.97 nm with a PDI of 0.694, and the zeta potential was −24.6 mV. The stability test results showed thatthe storage stability of RSV-AuNP-PEG was better than that of AuNP-RSV. Further, the RSV-AuNP-PEG was shown to be most stable in 2% bovine serumalbumin (BSA) while the AuNP-RSV was most stable in 2% BSA in phosphate-buffered saline pH 7.4.Conclusion: These results show that modification of RSV-conjugated AuNPs with PEG effectively prevents their aggregation in storage, but only incertain mediums.

Novel Bionic Biomembrane Supported by Gold Nanoparticles/Cellulose Hybrid Films

2012 ◽  
Vol 84 ◽  
pp. 13-18 ◽  
Author(s):  
Zhi Ming Liu ◽  
Yuan Lin An ◽  
Wen Jian Wu
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Solutions ◽  
Lipid Membranes ◽  
Hybrid Film ◽  
Bilayer Lipid Membranes ◽  
Hybrid Films ◽  
Bilayer Lipid ◽  
Long Period ◽  
Highly Active ◽  
The Stability

As one of the main methods to study biomembranes, the construction of highly active bionic biomembrane systems is very important. Based on the hybrid film of gold nanoparticles and cellulose, a novel system of bionic biomembrane is demonstrated. The ratio effects of lecithin to cholesterin on the stability of bilayer lipid membranes are studied. Lipid solutions that can form stable membranes in the air and in some aqueous solutions are prepared. The bionic biomembranes composed of bilayer lipid membranes and hybrid films of gold nanoparticles and cellulose can be sustained for a long period in aqueous solutions. The bionic biomembranes also exhibit some interesting electrochemical properties.

Chelating Tendencies of Some N-(2-Acetyl-1,3-Indandione) Trialkyl Ammonium Iodides with Transition Metal Ions

1973 ◽  
Vol 28 (5-6) ◽  
pp. 317-318 ◽  
Author(s):  
M. K. Bachlaus ◽  
K. L. Menaria ◽  
P. Nath
Keyword(s):  
Free Energy ◽  
Complex Formation ◽  
Transition Metal ◽  
Copper Complex ◽  
Dissociation Constants ◽  
Transition Metal Ions ◽  
Iron Complex ◽  
Potentiometric Studies ◽  
Kcal Mole ◽  
The Stability

The ligands T.P.A.I.* and T.B.A.I.** have been synthesised and their dissociation constants are 1.738 · 10-10 and 1.412 · 10-8 respectively. The potentiometric studies show that these reagents form 1 : 1 complex with copper(II) and iron(II). The stability constants of copper complex and iron complex with T.P.A.I. are 6.43 and 6.51 respectively and for T.B.A.I. 4.36 and 4.24 respectively. The free energy of complex formation at 25°C are 8.76 Kcal/mole and 8.87 Kcal/mole for Cu (II)-T.P.A.I. and Fe (II)-T.P.A.I. respectively, whereas the free energy of the Cu (II)-T.B.A.I. and Fe(II)-T.B.A.I. are 5.94 Kcal/mole and 5.78 Kcal/mole respectively.

Adsorbed Tween 80 is unique in its ability to improve the stability of gold nanoparticles in solutions of biomolecules

Nanoscale ◽  
2010 ◽  
Vol 2 (10) ◽  
pp. 2114 ◽  
Author(s):  
Yuyun Zhao ◽  
Zhuo Wang ◽  
Wei Zhang ◽  
Xingyu Jiang
Keyword(s):  
Gold Nanoparticles ◽  
Tween 80 ◽  
The Stability

scholarly journals Relative Stability of the Scleroglucan Triple-Helix and Single Strand: an Insight from Computational and Experimental Techniques

2016 ◽  
Vol 230 (9) ◽  
Author(s):  
Gianfranco Bocchinfuso ◽  
Claudia Mazzuca ◽  
Paolo Conflitti ◽  
Davide Cori ◽  
Tommasina Coviello ◽  
...  
Keyword(s):  
Relative Stability ◽  
Triple Helix ◽  
Hydrophobic Interactions ◽  
Single Strand ◽  
Single Chain ◽  
Ph Values ◽  
Partial Unfolding ◽  
Triplex Structure ◽  
Partially Unfolded ◽  
The Stability

AbstractScleroglucan (Sclg) is a polysaccharide that exhibits a triple helix conformation (triplex), both in aqueous solution and in the solid state, which is lost in DMSO solution, at high temperature and at high pH values. The triplex conformation is characterized by a high rigidity, responsible of Sclg peculiar properties. Although the relative stability of triplex and single strand has already been investigated, different structural details are still missing.In the present study, we analyse the structural properties and the factors stabilizing the single chain and the triple helix of Sclg in different conditions. To this end, we simulated both systems in water and in DMSO. The triple helix has been also simulated in the presence of chemical damages on one of the three strands (to reproduce in silico the effect of sonication) or by inducing a partial unfolding of the triplex structure. The computational results have been compared with experimental evidences in which the triplex denaturation, at alkaline pH values, has been followed by monitoring the UV and CD spectra of Congo red, used as a probe molecule. Our results indicate that sonication breaks the Sclg chains without appreciably changing the stability of the other tracts of triple helix. The simulated perturbed or partially unfolded triplexes show a clear tendency to form less ordered aggregates. Finally, our simulations put in evidence an important role of the hydrophobic interactions both in the triplex stability and in the aggregation processes observed after induced denaturation.

scholarly journals Role of the environment in the stability of anisotropic gold particles

2015 ◽  
Vol 17 (9) ◽  
pp. 6305-6313 ◽  
Author(s):  
Robinson Cortes-Huerto ◽  
Jacek Goniakowski ◽  
Claudine Noguera
Keyword(s):  
Gold Nanoparticles ◽  
Gold Particles ◽  
The Stability

We highlight the conditions under which energy differences between isotropic and elongated gold nanoparticles are reduced, thus prompting their thermodynamic coexistence.

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