scholarly journals Evaluating the Performance of a Magnetic Nanoparticle-Based Detection Method Using Circle-to-Circle Amplification

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 173
Author(s):  
Darío Sánchez Martín ◽  
Reinier Oropesa-Nuñez ◽  
Teresa Zardán Gómez de la Torre

This work explores several issues of importance for the development of a diagnostic method based on circle-to-circle amplification (C2CA) and oligonucleotide-functionalized magnetic nanoparticles. Firstly, the performance of the detection method was evaluated in terms of sensitivity and speed. Synthetic target sequences for Newcastle disease virus and Salmonella were used as model sequences. The sensitivity of the C2CA assay resulted in detection of 1 amol of starting DNA target with a total amplification time of 40 min for both target sequences. Secondly, the functionalization of the nanoparticles was evaluated in terms of robustness and stability. The functionalization was shown to be very robust, and the stability test showed that 92% of the oligos were still attached on the particle surface after three months of storage at 4 °C. Altogether, the results obtained in this study provide a strong foundation for the development of a quick and sensitive diagnostic assay.

2021 ◽  
Vol 22 (19) ◽  
pp. 10734
Author(s):  
Elena N. Velichko ◽  
Elina K. Nepomnyashchaya ◽  
Maksim A. Baranov ◽  
Alexey N. Skvortsov ◽  
Ivan V. Pleshakov ◽  
...  

In this study, interactions of Fe3O4 magnetic nanoparticles with serum albumin biomolecules in aqueous solutions were considered. The studies were conducted with the laser correlation spectroscopy and optical analysis of dehydrated films. It was shown that the addition of magnetite to an albumin solution at low concentrations of up to 10−6 g/L led to the formation of aggregates with sizes of up to 300 nm in the liquid phase and an increase in the number of spiral structures in the dehydrated films, which indicated an increase in their stability. With a further increase in the magnetite concentration in the solution (from 10−4 g/L), the magnetic particles stuck together and to albumin, thus forming aggregates with sizes larger than 1000 nm. At the same time, the formation of morphological structures in molecular films was disturbed, and a characteristic decrease in their stability occurred. Most stable films were formed at low concentrations of magnetic nanoparticles (less than 10−4 g/L) when small albumin–magnetic nanoparticle aggregates were formed. These results are important for characterizing the interaction processes of biomolecules with magnetic nanoparticles and can be useful for predicting the stability of biomolecular films with the inclusion of magnetite particles.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Nut Songvorawit ◽  
Kooranee Tuitemwong ◽  
Pravate Tuitemwong

The synthesis and characterization of amino-functionalized magnetic nanoparticles (amino-MNPs) were carried out. Amino-MNPs were prepared using polyol technique in an autoclave (121°C) without inert gas. The characterization of particles employed conventional SEM-EDS, TEM, XRD, FTIR, and VSM techniques. Results showed that amount of NaOH affected to the speed of MNP formation. The desirable uniform cubic shape of amino-MNPs was obtained from the addition of 2.50% w/v NaOH for 3 reaction cycles (2 hours/cycle). The amino-MNPs obtained from this condition have cubic shapes with the average size of 43 ± 9 nm. Results from elemental and structure analyses confirmed that the product was pure magnetite. The magnetic properties were ferromagnetism and were very close to a complete superparamagnetism. Fourier transform infrared (FT-IR) spectrum showed that the amino group existed on particle surface. The amino-MNPs of cubic shape were synthesized with facile single step at low temperature, and they have potential to be used for rapid microbial detection and many biological applications.


Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 668 ◽  
Author(s):  
Decsi ◽  
Krammer ◽  
Hegedűs ◽  
Ender ◽  
Gyarmati ◽  
...  

Biomimetic oxidation of drugs catalyzed by metalloporphyrins can be a novel and promising way for the effective and sustainable synthesis of drug metabolites. The immobilization of 5,10,15,20-tetrakis(2,3,4,5,6-pentafluorophenyl)iron(II) porphyrin (FeTPFP) and 5,10,15,20-tetrakis-(4-sulfonatophenyl)iron(II) porphyrin (FeTSPP) via stable covalent or rapid ionic binding on aminopropyl-functionalized magnetic nanoparticles (MNPs-NH2) were developed. These immobilized catalysts could be efficiently applied for the synthesis of new pharmaceutically active derivatives and liver related phase I oxidative major metabolite of an antiarrhythmic drug, amiodarone integrated in a continuous-flow magnetic chip reactor (Magnechip).


2015 ◽  
Vol 21 (42) ◽  
pp. 6038-6054 ◽  
Author(s):  
Dragoș Gudovan ◽  
Paul Balaure ◽  
Dan Mihăiescu ◽  
Adrian Fudulu ◽  
Bogdan Purcăreanu ◽  
...  

2021 ◽  
Vol 22 (3) ◽  
pp. 1477
Author(s):  
María Fuentes-Baile ◽  
Elizabeth Pérez-Valenciano ◽  
Pilar García-Morales ◽  
Camino de Juan Romero ◽  
Daniel Bello-Gil ◽  
...  

D-amino acid oxidase (DAAO) is an enzyme that catalyzes the oxidation of D-amino acids generating H2O2. The enzymatic chimera formed by DAAO bound to the choline-binding domain of N-acetylmuramoyl-L-alanine amidase (CLytA) induces cytotoxicity in several pancreatic and colorectal carcinoma and glioblastoma cell models. In the current work, we determined whether the effect of CLytA-DAAO immobilized in magnetic nanoparticles, gold nanoparticles, and alginate capsules offered some advantages as compared to the free CLytA-DAAO. Results indicate that the immobilization of CLytA-DAAO in magnetic nanoparticles increases the stability of the enzyme, extending its time of action. Besides, we compared the effect induced by CLytA-DAAO with the direct addition of hydrogen peroxide, demonstrating that the progressive generation of reactive oxygen species by CLytA-DAAO is more effective in inducing cytotoxicity than the direct addition of H2O2. Furthermore, a pilot study has been initiated in biopsies obtained from pancreatic and colorectal carcinoma and glioblastoma patients to evaluate the expression of the main genes involved in resistance to CLytA-DAAO cytotoxicity. Based on our findings, we propose that CLytA-DAAO immobilized in magnetic nanoparticles could be effective in a high percentage of patients and, therefore, be used as an anti-cancer therapy for pancreatic and colorectal carcinoma and glioblastoma.


2021 ◽  
Author(s):  
Emily Sheridan ◽  
Silvia Vercellino ◽  
Lorenzo Cursi ◽  
Laurent Adumeau ◽  
James A. Behan ◽  
...  

We describe how magnetic nanoparticles can be used to study intracellular nanoparticle trafficking, and how magnetic extraction may be integrated with downstream analyses to investigate nanoscale decision-making events.


2021 ◽  
Vol 22 (2) ◽  
pp. 654
Author(s):  
Ka Young Kim ◽  
Keun-A Chang

Parkinson’s disease (PD) is a progressive neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra. Several treatments for PD have focused on the management of physical symptoms using dopaminergic agents. However, these treatments induce various adverse effects, including hallucinations and cognitive impairment, owing to non-targeted brain delivery, while alleviating motor symptoms. Furthermore, these therapies are not considered ultimate cures owing to limited brain self-repair and regeneration abilities. In the present study, we aimed to investigate the therapeutic potential of human adipose-derived stem cells (hASCs) using magnetic nanoparticles in a 6-hydroxydopamine (6-OHDA)-induced PD mouse model. We used the Maestro imaging system and magnetic resonance imaging (MRI) for in vivo tracking after transplantation of magnetic nanoparticle-loaded hASCs to the PD mouse model. The Maestro imaging system revealed strong hASCs signals in the brains of PD model mice. In particular, MRI revealed hASCs distribution in the substantia nigra of hASCs-injected PD mice. Behavioral evaluations, including apomorphine-induced rotation and rotarod performance, were significantly recovered in hASCs-injected 6-OHDA induced PD mice when compared with saline-treated counterparts. Herein, we investigated whether hASCs transplantation using magnetic nanoparticles recovered motor functions through targeted brain distribution in a 6-OHDA induced PD mice. These results indicate that magnetic nanoparticle-based hASCs transplantation could be a potential therapeutic strategy in PD.


Author(s):  
Izabell Crăciunescu ◽  
Petru Palade ◽  
Nicuşor Iacob ◽  
George Marian Ispas ◽  
Anda Elena Stanciu ◽  
...  

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1136 ◽  
Author(s):  
Qiang Li ◽  
Fei Pan ◽  
Wentao Li ◽  
Dongya Li ◽  
Haiming Xu ◽  
...  

In this study, a novel 2-vinylpyridine functionalized magnetic nanoparticle (Mag-PVP) was successfully prepared. The prepared Mag-PVP was characterized by transmission electronic microscopy (TEM), Fourier transform infrared spectrophotometry (FT-IR), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA), and was used for the adsorption of bisphenol A (BPA) from aqueous solutions. Mag-PVP, which is composed of Fe3O4 nanoparticles and poly divinylbenzene-2-vinylpyridine (with a thickness of 10 nm), exhibited magnetic properties (Ms = 44.6 emu/g) and thermal stability. The maximum adsorption capacity (Qm) of Mag-PVP for BPA obtained from the Langmuir isotherm was 115.87 mg/g at 20 °C, which was more than that of Fe3O4 nanospheres. In the presence of NaCl, the improved adsorption capacity of Mag-PVP was probably attributed to the screening effect of Mag-PVP surface charge and salting-out effect. In the presence of CaCl2 and humic acid (HA), the adsorption capacity of BPA decreased due to competitive adsorption. The adsorption of BPA by Mag-PVP increased slightly with the increase in pH from 3.0 to 5.0 and obtained the largest adsorption amount at pH 5.0, which was probably attributed to hydrogen bonding interactions. Moreover, in actual water, Mag-PVP still showed excellent adsorption performance in removing BPA. The high adsorption capacity and excellent reusability performance in this work indicated that Mag-PVP was an effective adsorbent for removing BPA from aqueous solutions.


2021 ◽  
Vol 1092 (1) ◽  
pp. 012071
Author(s):  
Shah Samiur Rashid ◽  
Md. Belal Hossain Sikder ◽  
Mohd Hasbi Bin Ab. Rahim ◽  
Aizi Nor Mazila Binti Ramli ◽  
Rashidi Bin Roslan

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