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Tehrān, Iran

Dakterzada F.,Tarbiat Modares University | Mohabati Mobarez A.,Tarbiat Modares University | Habibi Roudkenar M.,High institute for Research and Education in Transfusion Medicine | Mohsenifar A.,Nanozino Co.
Vaccine | Year: 2016

Flagellin of Pseudomonas aeruginosa is an important vaccine candidate. N-terminal domains are highly conserved in both type a and type b flagellins. The efficacy of gold nanoparticles (AuNPs) conjugated to N-terminal domains of P. aeruginosa flagellin (flagellin(1-161)), as an immunogen in mice, has been assessed. The nanoparticles were conjugated to the recombinant protein through direct interaction of thiol molecules of the cysteines with AuNPs and formation of AuS bond. Flagellin(1-161), AuNP-flagellin(1-161), and flagellin(1-161) emulsified in Freund's adjuvant (FA: complete/incomplete Freund's adjuvant formulation) were administered subcutaneously to BALB/c mice. Mice given AuNP-flagellin(1-161) elicited high titers of anti-flagellin(1-161) antibodies compared with non-immune group and/or mice which received flagellin(1-161) without adjuvant. In whole cell ELISA, these antibodies effectively recognized the native flagellin on the bacteria. Opsonophagocytosis assay demonstrated the functional activity and specificity of anti-flagellin(1-161) antibodies raised by AuNP-flagellin(1-161) against homologous strain. All of the results were comparable with those obtained by use of FA. Taken together, this is the first report of conjugation of AuNPs to flagellin and evaluating its immune response against P. aeruginosa. © 2016 Elsevier Ltd. Source

Davarani F.H.,Islamic Azad University | Safarpour H.,Nanobiosensors Research Group | Safarpour H.,Pharmaceutical science Research Center | Safarnejad M.R.,Nanobiosensors Research Group | And 7 more authors.
Euphytica | Year: 2014

Identification of resistance resources of sugar beet germplasm against Polymyxa betae has always been a critical concern among sugar beet breeders. In the present study, two different methods including the DAS-enzyme-linked immunosorbent assay (ELISA) test and a nanobiosensor method based on florescent resonance transfer energy (FRET) were compared in order to achieve resistant germplasm. More specifically, 58 sugar beet germplasm as well as two negative and two positive controls were cultivated in infested soil under greenhouse conditions. The contamination level or in another words sensitivity and specificity observed based on the ELISA readings was inaccurately lower in comparison with the investigated nanobiosensor. Moreover, the nanobiosensor was 70 folds less time consuming compared to the ELISA method, for the immuno-reaction was much faster and no sample treatment steps were required. As a result, the quantum dots-FRET-based nanobiosensor investigated herein could well suit the task of everyday screening of resistance resource and could be efficiently used in breeding programs. © 2014, Springer Science+Business Media Dordrecht. Source

Khaksarinejad R.,Tarbiat Modares University | Mohsenifar A.,Nanozino Co. | Mohsenifar A.,Nanobiosensor Research Group | Rahmani-Cherati T.,Nanozino Co. | And 3 more authors.
Applied Biochemistry and Biotechnology | Year: 2015

Rapid detection of organophosphorous (OP) compounds such as paraoxon would allow taking immediate decision on efficient decontamination procedures and could prevent further damage and potential casualties. In the present study, a biosensor based on nanomagnet-silica core-shell conjugated to organophosphorous hydrolase (OPH) enzyme was designed for detection of paraoxon. Coumarin1, a competitive inhibitor of the OPH enzyme, was used as a fluorescence-generating molecule. Upon excitation of cumarin1 located at the active site of the enzyme, i.e., OPH, the emitted radiations were intensified due to the mirroring effect of the nanomagnet-silica core-shell conjugated to the enzyme. In presence of paraoxon and consequent competition with the fluorophore in occupying enzyme’s active site, a significant reduction in emitted radiations was observed. This reduction was proportional to paraoxon concentration in the sample. The method worked in the 10- to 250-nM concentration range had a low standard deviation (with a coefficient of variation (CV) of 6–10 %), and the detection limit was as low as 5 × 10−6 μM. © 2015, Springer Science+Business Media New York. Source

Zhaveh S.,Islamic Azad University at Tehran | Mohsenifar A.,Nanozino Co. | Mohsenifar A.,Nanosystems Research Team NRTeam | Beiki M.,Islamic Azad University at Tehran | And 5 more authors.
Industrial Crops and Products | Year: 2015

Herbal essential oils such as Cuminum cyminum are natural antifungal agents consisting of many different volatile compounds. In the present study, encapsulation by chitosan (CS)-caffeic acid (CA) nanogel was used to improve antimicrobial activity and stability of the C. cyminum essential oils against Aspergillus flavus. An encapsulation efficiency of 85% based on the optical density spectra of the essential oil was achieved and as revealed through the release kinetics studies, 78% of the encapsulated oils were released during 1 week. The results obtained indicated that due to the volatility and instability of the oils when exposed to environmental factors, its encapsulation considerably improved its performance. More specifically, the minimum inhibitory concentration of free and encapsulated C. cyminum essential oils against A. flavus under sealed condition were at 650 and 350. ppm, respectively. Moreover, the encapsulated oils performed better (800. ppm), when tested under non-sealed condition while the free oils failed to caused fungal growth inhibition within the concentration range tested (up to 1000. ppm). This finding could be of great significance in medicinal plant remedies in order to achieve improved performance of herbal essential oils at lower concentrations and during longer time frames. © 2015 Elsevier B.V. Source

Khalili S.T.,Islamic Azad University at Karaj | Mohsenifar A.,Nanozino Co. | Mohsenifar A.,Nanosystems Research Team NRTeam | Beyki M.,Islamic Azad University at Tehran | And 6 more authors.
LWT - Food Science and Technology | Year: 2015

This study was set to investigate the encapsulation of the Thyme essential oils using chitosan and benzoic acid-made nanogel in order to enhance its antifungal properties and half-life. To achieve this, the self-assembled polymer of chitosan and benzoic acid nanogel (CS-BA) was synthesized, its size and shape were confirmed by spectrometric (FTIR) and microscopic methods (TEM and SEM) and was then used in encapsulating the essence. Under sealed condition, the minimum inhibitory concentration of the CS-BA encapsulated essential oils was recorded at 300mg/l while the free Thyme extract could only completely prevent the growth of Aspergillus flavus at an elevated concentration of 400 mg/l. Under non-sealed condition, higher concentration of encapsulated Thyme essential oils (500 mg/l) was required to cause complete fungi inhibition and free oils failed to lead to full inhibition even at concentrations as high as 1000 mg/l. Invivo analysis also revealed significant anti-fugal properties of the encapsulated oils at concentrations above 700 mg/l. Overall, due to the volatility and instability of free essential oils, CS-BA nanogel encapsulation was found to have significantly increased half-life and the anti-fungal properties of Thyme essential oils. © 2014. Source

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