Publications by authors named "Mazaher Ahmadi"

28 Publications

  • Page 1 of 1

Enhancing autophagy in Alzheimer's disease through drug repositioning.

Pharmacol Ther 2022 Mar 16;237:108171. Epub 2022 Mar 16.

Department of Chemistry and Biochemistry, California State University, Fullerton, United States of America. Electronic address:

Alzheimer's disease (AD) is one of the biggest human health threats due to increases in aging of the global population. Unfortunately, drugs for treating AD have been largely ineffective. Interestingly, downregulation of macroautophagy (autophagy) plays an essential role in AD pathogenesis. Therefore, targeting autophagy has drawn considerable attention as a therapeutic approach for the treatment of AD. However, developing new therapeutics is time-consuming and requires huge investments. One of the strategies currently under consideration for many diseases is "drug repositioning" or "drug repurposing". In this comprehensive review, we have provided an overview of the impact of autophagy on AD pathophysiology, reviewed the therapeutics that upregulate autophagy and are currently used in the treatment of other diseases, including cancers, and evaluated their repurposing as a possible treatment option for AD. In addition, we discussed the potential of applying nano-drug delivery to neurodegenerative diseases, such as AD, to overcome the challenge of crossing the blood brain barrier and specifically target molecules/pathways of interest with minimal side effects.
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http://dx.doi.org/10.1016/j.pharmthera.2022.108171DOI Listing
March 2022

Wearable Potentiometric Sensor Based on NaMnO for Non-invasive Monitoring of Sodium Ions in Sweat.

Anal Chem 2022 02 20;94(4):2263-2270. Epub 2022 Jan 20.

Chemical Injuries Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran 1435916471, Iran.

Here, we present a wearable potentiometric ion sensor for real-time monitoring of sodium ions (Na) in human sweat samples using NaMnO as the sensing material. NaMnO is an attractive material for developing wearable electrochemical sensors due to its good Na incorporation ability, electrical conductivity, stability, and low fabrication cost. In the first step, the analytical performance of the electrode prepared using NaMnO is presented. Then, a miniaturized potentiometric cell integrated into a wearable substrate is developed, which reveals a Nernstian response (58 mV dec). We achieved the detection of Na in the linear ranges of 0.21-24.54 mmol L, which is well within the physiological range of Na. Finally, for on-body sweat analysis, the potentiometric sensor is fully integrated into a headband textile. This platform can be employed for non-invasive analysis of Na in human sweat for healthcare and disease diagnosis.
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http://dx.doi.org/10.1021/acs.analchem.1c04960DOI Listing
February 2022

Magnetic nanomaterials in analytical chemistry.

Talanta 2021 Dec 3;235:122762. Epub 2021 Aug 3.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran. Electronic address:

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http://dx.doi.org/10.1016/j.talanta.2021.122762DOI Listing
December 2021

Autophagy, Unfolded Protein Response, and Neuropilin-1 Cross-Talk in SARS-CoV-2 Infection: What Can Be Learned from Other Coronaviruses.

Int J Mol Sci 2021 Jun 1;22(11). Epub 2021 Jun 1.

Autophagy Research Center, Shiraz University of Medical Sciences, Shiraz 7134845794, Iran.

The COVID-19 pandemic is caused by the 2019-nCoV/SARS-CoV-2 virus. This severe acute respiratory syndrome is currently a global health emergency and needs much effort to generate an urgent practical treatment to reduce COVID-19 complications and mortality in humans. Viral infection activates various cellular responses in infected cells, including cellular stress responses such as unfolded protein response (UPR) and autophagy, following the inhibition of mTOR. Both UPR and autophagy mechanisms are involved in cellular and tissue homeostasis, apoptosis, innate immunity modulation, and clearance of pathogens such as viral particles. However, during an evolutionary arms race, viruses gain the ability to subvert autophagy and UPR for their benefit. SARS-CoV-2 can enter host cells through binding to cell surface receptors, including angiotensin-converting enzyme 2 (ACE2) and neuropilin-1 (NRP1). ACE2 blockage increases autophagy through mTOR inhibition, leading to gastrointestinal complications during SARS-CoV-2 virus infection. NRP1 is also regulated by the mTOR pathway. An increased NRP1 can enhance the susceptibility of immune system dendritic cells (DCs) to SARS-CoV-2 and induce cytokine storm, which is related to high COVID-19 mortality. Therefore, signaling pathways such as mTOR, UPR, and autophagy may be potential therapeutic targets for COVID-19. Hence, extensive investigations are required to confirm these potentials. Since there is currently no specific treatment for COVID-19 infection, we sought to review and discuss the important roles of autophagy, UPR, and mTOR mechanisms in the regulation of cellular responses to coronavirus infection to help identify new antiviral modalities against SARS-CoV-2 virus.
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http://dx.doi.org/10.3390/ijms22115992DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8199451PMC
June 2021

Emerging Advances of Nanotechnology in Drug and Vaccine Delivery against Viral Associated Respiratory Infectious Diseases (VARID).

Int J Mol Sci 2021 Jun 28;22(13). Epub 2021 Jun 28.

Laboratory for Innovations in Micro Engineering (LiME), Department of Mechanical Engineering, University of Victoria, Victoria, BC V8P 5C2, Canada.

Viral-associated respiratory infectious diseases are one of the most prominent subsets of respiratory failures, known as viral respiratory infections (VRI). VRIs are proceeded by an infection caused by viruses infecting the respiratory system. For the past 100 years, viral associated respiratory epidemics have been the most common cause of infectious disease worldwide. Due to several drawbacks of the current anti-viral treatments, such as drug resistance generation and non-targeting of viral proteins, the development of novel nanotherapeutic or nano-vaccine strategies can be considered essential. Due to their specific physical and biological properties, nanoparticles hold promising opportunities for both anti-viral treatments and vaccines against viral infections. Besides the specific physiological properties of the respiratory system, there is a significant demand for utilizing nano-designs in the production of vaccines or antiviral agents for airway-localized administration. SARS-CoV-2, as an immediate example of respiratory viruses, is an enveloped, positive-sense, single-stranded RNA virus belonging to the coronaviridae family. COVID-19 can lead to acute respiratory distress syndrome, similarly to other members of the coronaviridae. Hence, reviewing the current and past emerging nanotechnology-based medications on similar respiratory viral diseases can identify pathways towards generating novel SARS-CoV-2 nanotherapeutics and/or nano-vaccines.
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http://dx.doi.org/10.3390/ijms22136937DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8269337PMC
June 2021

Self-assembled graphene-based microfibers with eclectic optical properties.

Sci Rep 2021 Mar 9;11(1):5451. Epub 2021 Mar 9.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, 6517838695, Iran.

The construction of graphene-based microfibers with reinforced mechanical and electrical properties has been the subject of numerous researches in recent years. However, the fabrication of graphene-based fibers with remarkable optical features still remains a challenge and has not been addressed so far. This paper aims to report a series of flexible self-assembled fibers, synthesized through a few-minute sonication of thermally oxidized graphene oxide nanosheets, so-called Nanoporous Over-Oxidized Graphene (NOG), in an acidic medium. These free-standing glassy fibers were classified into four distinct morphological structures and displayed a collection of intriguing optical properties comprising high transparency, strong birefringence, fixed body colorations (e.g. colorless, blue, green, and red), tunable interference marginal colorations, UV-visible-near IR fluorescence, and upconversion emissions. Moreover, they exhibited high chemical stability in strongly acidic, basic, and oxidizing media. The foregoing notable attributes introduce the NOG fiber as a promising candidate both for the construction of graphene-based photoluminescent textiles and the development of a wide variety of optical applications.
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http://dx.doi.org/10.1038/s41598-021-84940-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7943562PMC
March 2021

Application of magnetic nanomaterials in electroanalytical methods: A review.

Talanta 2021 Apr 9;225:121974. Epub 2020 Dec 9.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran. Electronic address:

Magnetic nanomaterials (MNMs) have gained high attention in different fields of studies due to their ferromagnetic/superparamagnetic properties and their low toxicity and high biocompatibility. MNMs contain magnetic elements such as iron and nickel in metallic, bimetallic, metal oxide, and mixed metal oxide. In electroanalytical methods, MNMs have been applied as sorbents for sample preparation before the electrochemical detection (sorbent role), as the electrode modifier (catalytic role), and the integration of the above two roles (as both sorbent and catalytic agent). In this paper, the application of MNMs in electroanalytical methods have been classified based on the main role of the nanomaterial and discussed separately. Furthermore, catalytic activities of MNMs in electroanalytical methods such as redox electrocatalytic, nanozymes catalytic (peroxidase, catalase activity, oxidase activity, superoxide dismutase activity), catalyst gate, and nanocontainer have been discussed.
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http://dx.doi.org/10.1016/j.talanta.2020.121974DOI Listing
April 2021

Statins in patients with COVID-19: a retrospective cohort study in Iranian COVID-19 patients.

Transl Med Commun 2021 25;6(1). Epub 2021 Jan 25.

Health Policy Research Center, Institute of Health, Shiraz University of Medical Sciences, Shiraz, Iran.

Background: The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has profoundly affected the lives of millions of people. To date, there is no approved vaccine or specific drug to prevent or treat COVID-19, while the infection is globally spreading at an alarming rate. Because the development of effective vaccines or novel drugs could take several months (if not years), repurposing existing drugs is considered a more efficient strategy that could save lives now. Statins constitute a class of lipid-lowering drugs with proven safety profiles and various known beneficial pleiotropic effects. Our previous investigations showed that statins have antiviral effects and are involved in the process of wound healing in the lung. This triggered us to evaluate if statin use reduces mortality in COVID-19 patients.

Results: After initial recruitment of 459 patients with COVID-19 (Shiraz province, Iran) and careful consideration of the exclusion criteria, a total of 150 patients, of which 75 received statins, were included in our retrospective study. Cox proportional-hazards regression models were used to estimate the association between statin use and rate of death. After propensity score matching, we found that statin use appeared to be associated with a lower risk of morbidity [HR = 0.85, 95% CI = (0.02, 3.93),  = 0.762] and lower risk of death [(HR = 0.76; 95% CI = (0.16, 3.72),  = 0.735)]; however, these associations did not reach statistical significance. Furthermore, statin use reduced the chance of being subjected to mechanical ventilation [OR = 0.96, 95% CI = (0.61-2.99),  = 0.942] and patients on statins showed a more normal computed tomography (CT) scan result [OR = 0.41, 95% CI = (0.07-2.33),  = 0.312].

Conclusions: Although we could not demonstrate a significant association between statin use and a reduction in mortality in patients with COVID19, we do feel that our results are promising and of clinical relevance and warrant the need for prospective randomized controlled trials and extensive retrospective studies to further evaluate and validate the potential beneficial effects of statin treatment on clinical symptoms and mortality rates associated with COVID-19.
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http://dx.doi.org/10.1186/s41231-021-00082-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7829327PMC
January 2021

Ultrasound-assisted dispersive liquid antisolvent precipitation for extraction of polar organic compounds in water.

Anal Chim Acta 2020 Oct 20;1135:91-98. Epub 2020 Aug 20.

Department of Analytical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

This paper reports on the development of an extraction method called "ultrasound-assisted dispersive liquid antisolvent precipitation (UA-DLAP)". The developed method is a combination of dispersive liquid-liquid microextraction (DLLME) and liquid antisolvent precipitation (LAP) methods. Unlike DLLME, the extraction solvent in UA-DLAP is replaced with a bad solvent for the analyte which has a low affinity toward the analyte (antisolvent). Unlike LAP, in UA-DLAP the analyte is dissolved in water, the antisolvent is water-immiscible and denser than water, and the needed volume of the antisolvent is in microliter range. In UA-DLAP, after the addition of a mixture of the antisolvent and a disperser solvent to the sample solution under sonication, a cloudy mixture containing the antisolvent micro/nanodroplets appears. After centrifugation of the mixture, three phases appear (a water-rich phase in the top, an analyte rich precipitate phase in middle, and an antisolvent rich phase in the bottom). Finally, the analyte rich precipitate phase is separated and dissolved in a back-extraction solvent. To evaluate the efficiency of the UA-DLAP method and its possible mechanism of action, three model polar organic compounds in water were extracted by UA-DLAP and determined spectrophotometrically. The results showed that the precipitate phase for all of the investigated analytes was nanostructured. The limits of detection were 22 ng mL, 11 ng mL, and 3.9 ng mL for doxorubicin, methylene blue, and Congo red, respectively. Respective experimental enrichment factors were 18.3, 27.8, and 31.1.
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http://dx.doi.org/10.1016/j.aca.2020.08.027DOI Listing
October 2020

Pleiotropic effects of statins: A focus on cancer.

Biochim Biophys Acta Mol Basis Dis 2020 12 12;1866(12):165968. Epub 2020 Sep 12.

Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada; Health Policy Research Center, Institute of Health, Shiraz University of Medical Sciences, Shiraz, Iran; Research Institute of Oncology and Hematology, Cancer Care Manitoba, University of Manitoba, Winnipeg, Canada. Electronic address:

The statin drugs ('statins') potently inhibit hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase by competitively blocking the active site of the enzyme. Statins decrease de novo cholesterol biosynthesis and thereby reduce plasma cholesterol levels. Statins exhibit "pleiotropic" properties that are independent of their lipid-lowering effects. For example, preclinical evidence suggests that statins inhibit tumor growth and induce apoptosis in specific cancer cell types. Furthermore, statins show chemo-sensitizing effects by impairing Ras family GTPase signaling. However, whether statins have clinically meaningful anti-cancer effects remains an area of active investigation. Both preclinical and clinical studies on the potential mechanisms of action of statins in several cancers have been reviewed in the literature. Considering the contradictory data on their efficacy, we present an up-to-date summary of the pleiotropic effects of statins in cancer therapy and review their impact on different malignancies. We also discuss the synergistic anti-cancer effects of statins when combined with other more conventional anti-cancer drugs to highlight areas of potential therapeutic development.
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http://dx.doi.org/10.1016/j.bbadis.2020.165968DOI Listing
December 2020

Betulin and its derivatives as novel compounds with different pharmacological effects.

Biotechnol Adv 2020 Jan - Feb;38:107409. Epub 2019 Jun 18.

Department of Human Anatomy and Cell Science, Rady College of Medicine, Max Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada; Biology of Breathing Theme, Children Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, Canada; Health Policy Research Center, Institute of Health, Shiraz University of Medical Sciences, Shiraz, Iran; Research Institute of Oncology and Hematology, CancerCare Manitoba, University of Manitoba, Winnipeg, Canada. Electronic address:

Betulin (B) and Betulinic acid (BA) are natural pentacyclic lupane-structure triterpenoids which possess a wide range of pharmacological activities. Recent evidence indicates that B and BA have several properties useful for the treatment of metabolic disorders, infectious diseases, cardiovascular disorders, and neurological disorders. In the current review, we discuss B and BA structures and derivatives and then comprehensively explain their pharmacological effects in relation to various diseases. We also explain antiviral, antibacterial and anti-cancer effects of B and BA. Finally, we discuss the delivery methods, in which these compounds most effectively target different systems.
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http://dx.doi.org/10.1016/j.biotechadv.2019.06.008DOI Listing
February 2020

Autophagy and cancer research in Iran.

Autophagy 2019 11 23;15(11):2039-2042. Epub 2019 Apr 23.

Autophagy Research Center, Health Policy Research Center, Institute of Health, Shiraz University of Medical Sciences , Shiraz , Iran.

In August 2018, three events were held in Iran on clinical biochemistry, molecular biology, cancer/autophagy, laboratory management, and proteomics. On August 25-28 at the Isfahan University of Medical Sciences, the 15th National Biochemistry Congress and the 6th International Congress on Biochemistry and Molecular Biology were held, gathering together international professors from Canada, USA, Germany, Australia, Italy, France, and Sweden, as well as Iran to discuss mainly the roles of autophagy in cancer therapy. On August 29, a one-day 'Autophagy' symposium was held at the Shiraz University of Medical Sciences. The symposium was a place for specialist talks and discussions on the double-edged role of autophagy in cancer biology, which brought together approximately 200 participants, from basic and clinical fields who are interested in the autophagy field. Furthermore, the opening ceremony for the Autophagy Research Center was held on the same day, and the establishment of the center was announced in Shiraz.
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http://dx.doi.org/10.1080/15548627.2019.1606638DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6844528PMC
November 2019

Preparation and Characterization of Simvastatin Nanocapsules: Encapsulation of Hydrophobic Drugs in Calcium Alginate.

Methods Mol Biol 2020 ;2125:47-56

Department of Human Anatomy and Cell Science, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada.

During past few years, development of methods for physical encapsulation of drugs in biocompatible materials in mild conditions for poorly water-soluble hydrophobic drugs which are sensitive to hydrolytic conditions is of high interest in biomedical and pharmaceutical industries. The encapsulation can improve the drug solubility while decreases its side effects besides controlling its pharmacokinetic profile which results in the overall improvement of the therapeutic efficacy. In the current paper, we provide a detailed protocol for encapsulation of poorly water-soluble hydrophobic drugs which is a development of the previously developed protocol of nanocapsule formation by complex formation on the interface of emulsion droplets. The newly developed protocol is based on nanocapsule formation by complex formation on the interface of emulsion droplets except using no organic solvent for potential targeted drug delivery to glioblastoma cells. Simvastatin as a model of hydrophobic drugs of high hydrolytic sensitivity was encapsulated in calcium alginate hydrogel as a biocompatible matrix using the developed protocol. Simvastatin belongs to a group of mevalonate cascade inhibitors (statins) which have recently been considered as a possible new approach in cancer treatment especially glioblastoma. As a cholesterol biosynthesis inhibitor, it is very important to deliver statins only to target cells and not intact cells using targeted drug delivery strategies to avoid dysregulation of cholesterol biosynthesis in normal tissue. To prepare the statin drug nanocarrier's, the drug was first dissolved in polysorbate 20 nonionic surfactant solution, and then peptide modified calcium alginate was deposited on the micelles interface at neutral pH and 30 °C. The prepared nanocapsules were spherical in shape and very small in size (i.e., 17 ± 5 nm). The drug content of the nanocapsules was 117.3 mg g and the drug loading efficiency for a 5-mg initial amount of the drug was 23.5% ± 3.1%.
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http://dx.doi.org/10.1007/7651_2018_191DOI Listing
February 2021

Reduced graphene oxide as an efficient sorbent in microextraction by packed sorbent: Determination of local anesthetics in human plasma and saliva samples utilizing liquid chromatography-tandem mass spectrometry.

J Chromatogr B Analyt Technol Biomed Life Sci 2018 Sep 27;1095:177-182. Epub 2018 Jul 27.

Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden; Division of Materials and Nanofysik (MNF), KTH Royal Institute of Technology, Stockholm, Sweden. Electronic address:

Herein, reduced graphene oxide (RGO) has been utilized as an efficient sorbent in microextraction by packed sorbent (MEPS). The combination of MEPS and liquid chromatography-tandem mass spectrometry has been used to develop a method for the extraction and determination of three local anesthetics (i.e. lidocaine, prilocaine, and ropivacaine) in human plasma and saliva samples. The results showed that the utilization of RGO in MEPS could minimize the matrix effect so that no interfering peaks at the retention times of the analytes or internal standard was observed. The high extraction efficiency of this method was approved by mean recoveries of 97.26-106.83% and 95.21-105.83% for the studied analytes in plasma and saliva samples, respectively. Intra- and inter-day accuracies and precisions for all analytes were in good accordance with the international regulations. The accuracy values (as percentage deviation from the nominal value) of the quality control samples were between -2.1 to 13.9 for lidocaine, -4.2 to 11.0 for prilocaine and between -4.5 to -2.4 for ropivacaine in plasma samples while the values were ranged from -4.6 to 1.6 for lidocaine, from -4.2 to 15.5 for prilocaine and from -3.3 to -2.3 for ropivacaine in human saliva samples. Lower and upper limit of quantification (LLOQ, ULOQ) were set at 5 and 2000 nmol L for all of the studied drugs. The correlation coefficients values were ≥0.995. The limit of detection values were obtained 4 nmol L for lidocaine and prilocaine, and 2 nmol L for ropivacaine.
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http://dx.doi.org/10.1016/j.jchromb.2018.07.036DOI Listing
September 2018

Magnetic headspace adsorptive extraction of chlorobenzenes prior to thermal desorption gas chromatography-mass spectrometry.

Anal Chim Acta 2017 Jun 10;971:40-47. Epub 2017 Apr 10.

Department of Analytical Chemistry, Nutrition and Food Sciences and University Institute of Materials, University of Alicante, P.O. Box 99, E-03080, Alicante, Spain. Electronic address:

This study presents a new, user-friendly, cost-effective and portable headspace solid-phase extraction technique based on graphene oxide decorated with iron oxide magnetic nanoparticles as sorbent, located on one end of a small neodymium magnet. Hence, the new headspace solid-phase extraction technique has been called Magnetic Headspace Adsorptive Extraction (Mag-HSAE). In order to assess Mag-HSAE technique applicability to model analytes, some chlorobenzenes were extracted from water samples prior to gas chromatography-mass spectrometry determination. A multivariate approach was employed to optimize the experimental parameters affecting Mag-HSAE. The method was evaluated under optimized extraction conditions (i.e., sample volume, 20 mL; extraction time, 30 min; sorbent amount, 10 mg; stirring speed, 1500 rpm, and ionic strength, non-significant), obtaining a linear response from 0.5 to 100 ng L for 1,3-DCB, 1,4-DCB, 1,2-DCB, 1,3,5-TCB, 1,2,4-TCB and 1,2,3-TCB; from 0.5 to 75 ng L for 1,2,4,5-TeCB, and PeCB; and from 1 to 75 ng L for 1,2,3,4-TeCB. The repeatability of the proposed method was evaluated at 10 ng L and 50 ng L spiking levels, and coefficients of variation ranged between 1.5 and 9.5% (n = 5). Limits of detection values were found between 93 and 301 pg L. Finally, tap, mineral and effluent water were selected as real water samples to assess method applicability. Relative recoveries varied between 86 and 110% showing negligible matrix effects.
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http://dx.doi.org/10.1016/j.aca.2017.04.002DOI Listing
June 2017

Nanomaterials as sorbents for sample preparation in bioanalysis: A review.

Anal Chim Acta 2017 03 7;958:1-21. Epub 2016 Dec 7.

Department of Environmental and Analytical Chemistry, Stockholm University, SE10691 Stockholm, Sweden. Electronic address:

In recent years, application of nanomaterials as sorbent has gained the attention of researchers in bioanalysis. Different nanomaterials have been utilized as the sorbent in extraction techniques such as solid phase extraction, dispersive solid phase extraction, magnetic solid phase extraction, microextraction by packed sorbent, solid phase microextraction, dispersive μ-solid phase extraction, and stir bar sorptive extraction. In the present review, different nanomaterials which have recently been utilized as sorbent for bioanalysis are classified into six main groups, namely metallic, metallic and mixed oxide, magnetic, carbonaceous, silicon, and polymer-based nanomaterials. Application of these nanomaterials in different extraction techniques for bioanalysis has been reviewed. This study shows that magnetic nanomaterials have gained significant attention owing to their magnetic separation ability. In addition, the present review shows that there is a lack in the application of nanomaterials for on-line analysis procedures, most probably due to some intrinsic properties of nanomaterials such as spontaneous agglomeration.
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http://dx.doi.org/10.1016/j.aca.2016.11.062DOI Listing
March 2017

Determination of ᴅ-phenylglycine in the presence of its ʟ-enantiomer using a turn-on fluorescent nano-chemosensor.

Talanta 2017 Jan 13;162:547-551. Epub 2016 Oct 13.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

This paper reports on application of ʟ-tryptophan modified magnetite nanospheres (TryMNSs) as a novel fluorescent chiral selector for selective and sensitive determination of ᴅ-phenylglycine (ᴅ-Phy) in the presence of its enantiomer (i.e. ʟ-phenylglycine, ʟ-Phy). The results showed that the nanospheres could be used as a "turn-on" fluorescence nanosensor based on enhancement of its fluorescence peak intensity in the presence of ᴅ-Phy. Unlike its enantiomer, ʟ-Phy did not affect the nanosensor fluorescence behaviour suggesting that using the synthesized nanospheres selective determination of ᴅ-Phy in the presence of ʟ-Phy was achievable. The enhancing effect can be attributed to the initial formation of hydrogen-bonded complex followed by π-π interaction between the aromatic tryptophan moieties and ᴅ-Phy. After various affecting factors optimizing, the results showed that using the enhancing effect, selective and sensitive determination of ᴅ-Phy in the presence of ʟ-Phy in the concentration range of 0.5-200.0mgL with a detection limit as low as 190ngmL was achievable.
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http://dx.doi.org/10.1016/j.talanta.2016.10.054DOI Listing
January 2017

Determination of AZD6118 in dog plasma samples utilizing microextraction by packed sorbent and liquid chromatography-electrospray ionization tandem mass spectrometry.

J Chromatogr B Analyt Technol Biomed Life Sci 2017 Feb 4;1043:20-24. Epub 2016 Nov 4.

Department of Environmental Sci. & Analytical Chemistry, Stockholm University, SE10691 Stockholm, Sweden. Electronic address:

In this work, for the first time, a method has been developed for the determination of AZD6118, a candidate drug, in dog plasma samples. The method is based on microextraction by packed sorbent (MEPS) of the drug prior to liquid chromatography-electrospray ionization tandem mass spectrometry assay. Various important factors affecting MEPS performance were optimized, and under the optimized condition, a linear calibration curve in the concentration range of 20-25,000nmolL with a coefficient of determination over 0.99 was obtained. The back-calculated values of the calibration points showed good agreement with the theoretical concentrations (coefficients of variation percent between 0.3-3.8). The lower limit of quantification and limit of detection were 20.0 and 2.9nmolL, respectively. The repeatability and accuracy of the method was evaluated by determination of quality control samples at three concentration levels (low, medium and high) using the developed method, and the results (coefficients of variation values were between 1.9% and 3.2%, relative recoveries ranged between 93.5-102.1%) confirm that a powerful method has been developed for the extraction and determination of the investigated drug in dog plasma.
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http://dx.doi.org/10.1016/j.jchromb.2016.11.004DOI Listing
February 2017

Solid phase extraction of amoxicillin using dibenzo-18-crown-6 modified magnetic-multiwalled carbon nanotubes prior to its spectrophotometric determination.

Talanta 2016 22;148:122-8. Epub 2015 Oct 22.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

This work reports on a method for selective extraction and sensitive determination of amoxicillin drug (AMX). The method is based on solid phase extraction of AMX by a novel modified magnetic nanoadsorbent prior to spectrophotometric determination of AMX using a procedure based on formation a colored azo-derivative of the investigated drug. The nanoadsorbent has been synthesized by modification of magnetic-multiwalled carbon nanotube with dibenzo-18-crown-6 moieties. The synthesized nanoparticles were characterized using TEM, XRD and FT-IR measurements. At the next step, various factors that could potentially affect adsorption and desorption efficiencies of AMX, have been optimized. The results showed that under the optimized conditions, sensitive and selective determination of the investigated drug in concentration range of 5.0-1000.0 ng mL(-1) with the limit of detection of 3.0 ng mL(-1) was achievable. Furthermore, the real sample analysis (i.e. amoxicillin capsules and human urine samples) results indicated that a reliable promising candidate method has been developed for the determination of AMX in the investigated real samples.
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http://dx.doi.org/10.1016/j.talanta.2015.10.051DOI Listing
September 2016

Construction a magneto carbon paste electrode using synthesized molecularly imprinted magnetic nanospheres for selective and sensitive determination of mefenamic acid in some real samples.

Biosens Bioelectron 2015 Jun 3;68:712-718. Epub 2015 Feb 3.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

A novel magneto multiwalled carbon nanotube/carbon paste electrode (MMW/CPE) for the determination of mefenamic acid (MFA) was introduced. Magnetic molecularly imprinted polymer nanoparticles (MMIPNPs) were synthesized and then added to the solution of MFA. After stirring for 20 min, the MMW/CPE was immersed in the solution of MFA (contain MMIPNPs) and the MMIPNPs were captured by it. Then oxidation of MFA was analyzed by differential pulse voltammetry (DPV). Electrochemical impedance spectroscopy, cyclic voltammetry, and DPV were employed to characterize the MMW/CPE. The MMIPNPs exhibited a high selectivity and sensitivity toward MFA. The effect of various experimental parameters including pH, MMIPNPs dosage, stirring time, accumulation potential and time on the voltammetric response of MFA were investigated. Under the optimal conditions, selective detection of MFA in a linear concentration range of 2.0-1000.0 nmol L(-1) was performed with the detection limit of 1.2 nmol L(-1) (3S/N). To further study the practical applicability of this method, it was applied to the analysis of some real samples and the obtained results were satisfactory.
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http://dx.doi.org/10.1016/j.bios.2015.02.001DOI Listing
June 2015

Molecularly imprinted polymer coated magnetite nanoparticles as an efficient mefenamic acid resonance light scattering nanosensor.

Anal Chim Acta 2014 Dec 26;852:250-6. Epub 2014 Sep 26.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

In this work, a mefenamic acid (MFA) nanosensor was synthesized by the aid of molecularly imprinted polymer (MIP) technique. MIP layer was coated on magnetite nanoparticles as magnetic nano-carriers. Synthesized nanoparticles were characterized using various measurements techniques. Light scattering properties of the synthesized nanoparticles in the presence or absence of MFA have been selected as the detection signal. In this regard, resonance light scattering has been used as the detection method. Various factors that can potentially affect light scattering efficiency (i.e., pH, ultrasonication time and nanoparticle dosage) were optimized using "one-at-a-time" method. A linear dynamic range was established from 100.0 to 2000.0 ng L(-1) of MFA and the limit of detection was found to be 50.0 ng L(-1) using the proposed method.
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http://dx.doi.org/10.1016/j.aca.2014.09.039DOI Listing
December 2014

Preconcentration and spectrophotometric determination of oxymetholone in the presence of its main metabolite (mestanolone) using modified maghemite nanoparticles in urine sample.

Talanta 2013 Oct 11;115:468-73. Epub 2013 Jun 11.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran. Electronic address:

A novel and sensitive extraction procedure using maghemite nanoparticles (γ-Fe2O3) modified with sodium dodecyl sulfate (SDS), as an efficient solid phase, was developed for removal, preconcentration and spectrophotometric determination of trace amounts of oxymetholone (OXM), in the presence of mestanolone (MSL). Combination of nanoparticle adsorption and easily magnetic separation was used for the extraction and desorption of OXM. The preparation of γ-Fe2O3 nanoparticles were obtained by co-precipitation method and their surfaces were modified by SDS. The size and properties of the produced γ-Fe2O3 nanoparticles were determined by X-ray diffraction analysis, FT-IR and scanning electron microscopy measurements. OXM and MSL became adsorbed at pH 3.0. The adsorbed drugs were then desorbed and determined spectrophotometrically using a selective complexation reaction for OXM. The calibration graph was linear in the range 15.0-3300.0 ng mL(-1) of OXM with a correlation coefficient of 0.9948. The detection limit of the method for determination of OXM was 4.0 ng mL(-1). The method was applied for the determination of OXM in human urine samples.
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http://dx.doi.org/10.1016/j.talanta.2013.05.056DOI Listing
October 2013

Selective solid-phase extraction of naproxen drug from human urine samples using molecularly imprinted polymer-coated magnetic multi-walled carbon nanotubes prior to its spectrofluorometric determination.

Analyst 2013 Aug 6;138(16):4542-9. Epub 2013 Jun 6.

Faculty of Chemistry, Bu Ali Sina University, Hamedan, Iran.

A drug imprinted polymer based on suspension polymerization on magnetic multi-walled carbon nanotubes (MIPMCNTs) was prepared with a synthesized amidoamine as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, naproxen (NAP) as the template and ammonium persulfate as the initiator. The MIPMCNTs were characterized by TEM, FT-IR and XRD measurements. The prepared magnetic adsorbent can be well dispersed in aqueous media and can be easily separated magnetically from the medium after loading with NAP. All the aspects influencing the adsorption (extraction time, adsorbent dosage and pH) and desorption (desorption time and desorption solvent) of the analyte on the MIPMCNTs have been investigated. The extracted NAP could be easily desorbed with a mixture of methanol/sodium hydroxide aqueous solution and determined spectrofluorometrically at λem = 353 nm (λex = 271 nm). A linear dynamic range was established from 4.0 to 40.0 ng mL⁻¹ of NAP and the limit of detection (LOD) was found to be 2.0 ng mL⁻¹. In addition, the equilibrium adsorption data of NAP by imprinted polymer were analyzed by Langmuir and Freundlich isotherm models. The developed method was utilized for the determination of NAP in human urine samples with satisfactory results.
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http://dx.doi.org/10.1039/c3an00686gDOI Listing
August 2013

Superparamagnetic surface molecularly imprinted nanoparticles for sensitive solid-phase extraction of tramadol from urine samples.

Talanta 2013 Feb 31;105:255-61. Epub 2012 Dec 31.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

A rapid, selective, sensitive and accurate method based on superparamagnetic molecularly imprinted polymer nanoparticles (MMIPNPs) was developed for the determination of tramadol (TRA) in human urine samples. The MMIPNPs were prepared by coating SiO2-Fe3O4 nanoparticles with polyaminoimide homopolymer and TRA as the template. The prepared MMIPNPs adsorbent was characterized by TEM, FT-IR, XRD and magnetometry. TEM images show that the Fe3O4 nanoparticles are well-enwrapped by the SiO2 shell and further by an MIP layer. The prepared magnetic adsorbent is well dispersed in water and can be easily separated magnetically from the medium after loading with the adsorbate. Various parameters affecting the extraction efficiency of the MMIPNPs have been evaluated. The extracted TRA could be easily desorbed with a mixture of methanol and acetic acid and determined spectrophotometrically at 272 nm. A linear dynamic range was established from 3.0 to 200.0 ng mL(-1) of TAR and the limit of detection was found to be 1.5 ng mL(-1). The proposed method was successfully applied for the determination of TRA in human urine samples.
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http://dx.doi.org/10.1016/j.talanta.2012.12.039DOI Listing
February 2013

Fabrication of a new electrochemical sensor based on a new nano-molecularly imprinted polymer for highly selective and sensitive determination of tramadol in human urine samples.

Biosens Bioelectron 2013 Jun 16;44:34-40. Epub 2013 Jan 16.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

A new nano-molecularly imprinted polymer bead was synthesized and applied to the fabrication of a chemically modified carbon paste electrode. Nano-molecularly imprinted polymer with molecular recognition capacity was made-up by using [email protected] as the core and the supporting material. The electrode was applied to the simple, rapid, highly selective and sensitive determination of tramadol using square wave voltammetry. The molecularly imprinted polymer and multi-walled carbon nanotubes modified carbon paste electrode was prepared by incorporating the synthesized nano-MIP and multi-walled carbon nanotubes in carbon paste electrode. The limit of detection and the linear range were found to be 0.004 and 0.01 to 20 μmol L(-1) of tramadol, respectively. The effects of potentially interfering substances on the determination of this compound were investigated. And it was found that the electrode is highly selective. The proposed chemically modified carbon paste electrode was used for the determination of tramadol in infected and healthy human urine and pharmaceutical samples.
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http://dx.doi.org/10.1016/j.bios.2012.11.030DOI Listing
June 2013

Adsorption and kinetic studies of seven different organic dyes onto magnetite nanoparticles loaded tea waste and removal of them from wastewater samples.

Spectrochim Acta A Mol Biomol Spectrosc 2012 Dec 16;99:102-9. Epub 2012 Sep 16.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

Adsorption of seven different organic dyes from aqueous solutions onto magnetite nanoparticles loaded tea waste (MNLTW) was studied. MNLTW was prepared via a simple method and was fully characterized. The properties of this magnetic adsorbent were characterized by scanning electron microscopy and X-ray diffraction. Adsorption characteristics of the MNLTW adsorbent was examined using Janus green, methylene blue, thionine, crystal violet, Congo red, neutral red and reactive blue 19 as adsorbates. Dyes adsorption process was thoroughly studied from both kinetic and equilibrium points of view for all adsorbents. The experimental isotherm data were analyzed using Langmuir, Freundlich, Sips, Redlich-Peterson, Brouers-Sotolongo and Temkin isotherms. The results from Langmuir isotherm indicated that the capacity of MNLTW for the adsorption of cationic dyes was higher than that for anionic dyes. The adsorption kinetics was tested for the pseudo-first order and pseudo-second order kinetic models at different experimental conditions.
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http://dx.doi.org/10.1016/j.saa.2012.09.025DOI Listing
December 2012

Simple in situ functionalizing magnetite nanoparticles by reactive blue-19 and their application to the effective removal of Pb2+ ions from water samples.

Chemosphere 2013 Jan 25;90(2):542-7. Epub 2012 Sep 25.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

An in situ method for direct attachment of reactive blue-19 onto the surface of magnetite nanoparticles to prepare an efficient adsorbent for removal of Pb(2+) ion from water samples was proposed. The produced modified magnetite nanoparticles (MMNP) were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and infrared spectroscopy. The synthesized MMNP showed high adsorption capacity to removal of Pb(2+) from wastewater samples. Lead ion adsorption process has been thoroughly studied from both kinetic and equilibrium points of view for adsorbent. The adsorption isotherms were analyzed using the five different isotherm models and correlation coefficients were determined for each isotherm. It was found that the Langmuir isotherm showed better correlation with the experimental data than other isotherms. The adsorption kinetics was tested for the pseudo-first order and pseudo-second order kinetic models at different experimental conditions. The kinetic data showed that the process is very fast and the adsorption process follows pseudo second order kinetic models for modified magnetite adsorbents. Thus, the new nanoparticles are favorable and useful for the removal of this metal ion, and the high adsorption capacity makes them good promising candidate materials for Pb(2+) ion removal from water samples.
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http://dx.doi.org/10.1016/j.chemosphere.2012.08.025DOI Listing
January 2013

Removal of some cationic dyes from aqueous solutions using magnetic-modified multi-walled carbon nanotubes.

J Hazard Mater 2011 Nov 6;196:109-14. Epub 2011 Sep 6.

Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Iran.

An adsorbent, magnetic-modified multi-walled carbon nanotubes, was used for removal of cationic dyes crystal violet (CV), thionine (Th), janus green B (JG), and methylene blue (MB) from water samples. Prepared nanoparticles were characterized by SEM, TEM, BET and XRD measurements. The prepared magnetic adsorbent can be well dispersed in the water and easily separated magnetically from the medium after loaded with adsorbate. The influences of parameters including initial pH, dosage of adsorbent and contact time have been investigated in order to find the optimum adsorption conditions. The optimum pH for removing of all the investigated cationic dyes from water solutions was found to be 7.0. The experimental data were analyzed by the Langmuir adsorption model. The maximum predicted adsorption capacities for CV, JG, Th and MB dyes were obtained as 227.7, 250.0, 36.4 and 48.1 mg g(-1), respectively. Desorption process of the adsorbed cationic dyes was also investigated using acetonitrile as the solvent. It was notable that both the adsorption and desorption of dyes were quite fast probably due to the absence of internal diffusion resistance.
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http://dx.doi.org/10.1016/j.jhazmat.2011.08.078DOI Listing
November 2011
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