Search

In this paper, the synthesis of a selective fluorescence “turn-on” nanosensor for methamphetamine (MA) based on a new 1,8-naphthalimide-thiophene derivative (NTS) and its immobilization on the surface of the nano-silica particles (NTS@SiO 2 ) is described. The sensory ability of NTS and NTS@SiO 2 toward MA is studied in solution and solid state. NTS displays significant fluorescence enhancement of (7.3-fold) in the presence of MA and much more intensified after being attached to nanosilica particles (15.39-fold) due to nanostructure effect. NTS@SiO 2 showed high sensitivity to MA vapor in solid state as well as in solution. The emission of NTS@SiO 2 in the film state exhibited a fast and reversible response to MA vapor with a linear correlation in the range of 6.7 μmol L −1 to 0.27 mmol L −1 . The analytical applicability of the present nanosensor has been studied by parallel technique of high-performance liquid chromatography. [ABSTRACT FROM AUTHOR]

A method utilizing NMR spectroscopy has been developed to confirm the identity and quantity of levodopa, carbidopa and methyldopa in human serum and pharmaceutical preparations. The method is based on 500MHz proton NMR spectra of individual catecholamine molecules. Qualitative and quantitative analyses are based on resonance characteristics of the functional groups present in their structures and the integral ratio of selected signals belonging to different compounds with respect to those of an internal standard, respectively. Experiments are performed to validate the quantitative NMR method, and the linearity and reproducibility of the proposed method are verified. The detection limit of the proposed method was estimated as 4.2, 1.7 and 1.6 μgml−1 for levodopa, carbidopa and methyldopa, respectively. The recovery studies performed on human serum samples ranged from about 82–96% with relative standard deviations of < 4%. The method was also applied successfully to the determination of each active compound in real pharmaceutical samples, and compared with the results obtained by the reference methods. The method is rapid, precise, accurate, and suitable for routine analyses. [Copyright &y& Elsevier]

The use of conventional gadolinium(Gd)-based contrast agents in magnetic resonance imaging (MRI) poses a significant risk of Nephrogenic Systemic Fibrosis (NSF) syndrome in patients with impaired renal function (grades 4 and 5). To address this issue, a new study has introduced a novel metabolic Gadolinium oxide nanoparticle (Gd2O3 NPs) coated with β-cyclodextrin (βCD). The study aims to investigate NSF syndrome by quantifying tissue Gd deposition biodistribution in renal impairment rats using MR molecular imaging. This is the first study of its kind to use this approach. A group of 20 rats were divided into four groups, each containing five rats that underwent 5/6 nephrectomy. The rats received 12 intravenous injections of a novel homemade synthesized gadolinium oxide polycyclodextrin (Gd2O3@PCD) at a dose of 0.1 mmol/kg, conventional contrast agents (CAs) drugs of Omniscan (Gd-DTPA-BMA) and Dotarem (Gd-DOTA), at a dose of 2.5 mmol/kg, and 250 μl saline for two injections per week during six weeks. T1-weighted MR imaging was performed before the injections and once a week for six weeks to quantify Gd deposition in four different organs (skin, liver, heart, and lung) in rats using inductively coupled plasma mass spectrometry (ICP-MS). The relationship between Signal-to-Noise Ratio (SNR) and biodistribution of Gd deposition due to NSF-induced syndrome was also calculated. The results of the study showed that the Gd concentrations in tissues were significantly higher in the Gd2O3@PCD group compared to the other groups, without any significant histopathological changes (P < 0.05). In the Gd2O3@PCD group, Gd was mainly deposited in the skin, followed by the liver, lung, and heart, without any symptoms of thickening or hardening of the skin. The Gd concentrations in the skin, liver, lung, and heart were significantly lower in the Dotarem group than in the Omniscan group (P < 0.05). In the histopathological examinations, the Omniscan group showed increased cellularity in the dermis. A significant hyperintensity was observed in the Gd2O3@PCD-treated rats compared to the Dotarem and Omniscan groups in the liver, heart, and lung. Compared to conventional Gd-based CAs, the novel metabolically Gd2O3@PCD with increased SNR, biosafety, and a considerably lower probability of developing NSF, has potential applicability for diagnosing patients with renal diseases in clinical MR Molecular Imaging (MRMI). [Display omitted] • To prevent Nephrogenic-Systemic-Fibrosis(NSF) risk in Renal Failure Patients, Gd2O3@PCD is used as a new Morphological-Metabolical and Biocompatible Gadolinium-based nanomagnetic Contrast Agent(GBCAs) in Molecular MRI, with the potential applicability in MRI for the Patients with GFR ≥4 • Gd2O3@PCD provided higher SNR, with a considerably lower dose of 0.2 mmol/kg, compared to the conventional dose of 2.5 mmol/kg for Dotarem/Omniscan as clinical GBCAs, for Imaging of significant-organs like heart, liver, and lung. • Gd2O3@PCD minimized the risk of NSF in the 5/6-nephrectomy-rat by increasing biosafety parameters measured by ICP-MS, MTT, and histopathological-analysis [ABSTRACT FROM AUTHOR]

Abstract: 19F NMR spectroscopy was applied to the quantitative determination of fluoxetine enantiomers using different chiral recognition agents in pharmaceutical formulations. Several parameters affecting the enantioresolution including the type and concentration of chiral selector, concentration of fluoxetine and temperature were studied. The chiral selectors investigated are the cyclic oligosaccharides α-, β- and γ-cyclodextrin and a diamino derivative of methylated α-cyclodextrin (DAM-α-CD), linear polysaccharides (maltodextrin with dextrose equivalents of 4.0–7.0, 13.0–17.0 and 16.5–19.5) and the macrocyclic antibiotic vancomycin. Among the chiral selectors used, DAM-α-CD turned out to give the best resolution of the 19F NMR signals of (R)- and (S)-fluoxetine. The calibration curve was linear for (R)- and (S)-fluoxetine over the range 0.10–1.35mgmL−1, the detection limits (S/N=3) being 5.9 and 7.5μgmL−1 for the pure solutions of (R)- and (S)-fluoxetine, respectively. The recovery studies performed on pharmaceutical samples ranged from about 90 to 110% with relative standard deviations of <8%. The results showed that the proposed method is rapid, precise and accurate. Applying statistical Student''s t-test revealed insignificant difference between the real and measured contents at the 95% confidence level. [Copyright &y& Elsevier]

Overcoming the tumor radioresistance along with protecting the adjacent normal tissues is considered as the ultimate goal of the radiation therapy. To achieve this goal, extensive studies have demonstrated the radiosensitization potential of the gold nanoparticles (AuNPs) during treatment with low-energy ionizing radiation due to their high-photoelectric absorption coefficient. Compared to the AuNPs, the bismuth nanoparticles (BiNPs) with higher atomic number, low cost, high biocompatibility and high biodegradability are attractive candidates for amplifying the radiation dose. Accordingly, the aim of this study was to quantify dose enhancement factors (DEFs) from BiNPs compared to AuNPs at clinically relevant energies. To quantitatively monitor the three-dimensional distribution of the absorption dose, we synthesized the nPAG polymer gel impregnated with 0.2 mM (0.04 mg/ml tissue) of AuNPs and BiNPs separately. In parallel, the samples were exposed to iridium-192 internal (380 keV) and cobalt-60 external (1.25 MeV) sources to explore the effect of energy. Finally, the R2-weighted dose maps of the calibration and test tubes were acquired by a Siemens 1.5 T MRI scanner. The mean dose enhancements obtained by AuNPs and BiNPs following irradiation of iridium-192 source were 14.72% ± 0.34 and 16.35% ± 0.38, respectively. Conversely, these values decreased to less than 4% for the samples irradiated with cobalt-60 γ-rays. Taken together, our experimental results suggest BiNPs-enhanced iridium-192 brachytherapy can potentially be a promising therapeutic tool in improving the efficacy of cancer radiation therapy. However, enhancement factors obtained from the cobalt-60 source decreased more significantly, highlighting the strong energy dependence of dose enhancement. •A bismuth nanoparticle induced-dose enhancement of 16% in the Ir-192 brachytherapy •14% of dose enhancement due to gold nanoparticles during the Ir-192 brachytherapy •The negligible dose escalation of Co-60 source from the investigated nanoparticles •Measurement of the 3D dose distribution of nanoparticles by the MRI gel dosimetry [ABSTRACT FROM AUTHOR]

Recently DNA aptamers have attracted remarkable attention as possible targeting ligands since selective targeting of cancer cells is a critical step in cancer diagnosis and therapy. Here, the development of AS1411 aptamer-functionalized albumin nanoparticles loaded on iron oxide and gold nanoparticles is reported for target delivery of the well-known anticancer drug of doxorubicin (Dox). Iron oxide nanoparticles (IONPs) and gold nanoparticles (GNPs) were prepared by ultrasound-assisted and controlled seeded growth synthetic methods, respectively. The nanocarrier was synthesized by a desolvation cross-linking method and characterized by dynamic light scattering, zeta potential measurement, thermogravimetric analysis, transmission electron microscopy, as well as vibrating sample magnetometer. The synthesized nanoparticles were found to be spherical with an average diameter of 120 nm and zeta potential of about −50.3 mV. The in-vitro anti-tumor effect of the designed delivery vehicle on MCF7 and SKBR3 human cancer cells was evaluated by MTT assay. The experimental results revealed that it could significantly inhibit the proliferation of cancerous cells. Moreover, GNPs and IONPs with the coating of albumin did not show any toxicity. AS1411 aptamer-functionalized nanoparticles improved cellular uptake and efficiency to MCF7 breast cancer cells as compared to non-targeting nanoparticles because of the high affinity of mentioned aptamer toward the overexpressed nucleolin on MCF7 cell surface. [ABSTRACT FROM AUTHOR]

Abstract: 19F nuclear magnetic resonance was used as a suitable analytical tool for the identification and selective determination of haloperidol in human serum and pharmaceutical preparations. The method is based on the integration of appropriate signals of haloperidol and trifluoroacetic acid as an internal standard. The proposed method is a rapid and facile, while without any sample pretreatment, manipulation of large samples and lengthy instrument time. The regression equation for haloperidol in human serum showed a good linearity in the range of 60–600μgml−1 with a detection limit of 1.4μgml−1. The mean recovery results on human serum samples ranged from about 96–103%, with relative standard deviations <8%. The method was also applied successfully to the determination of haloperidol in real pharmaceutical samples, and compared with the results obtained by a reference method. The drug''s degradation was studied by the proposed method in hydrochloric acid media and main products were identified. [Copyright &y& Elsevier]

A PVC-based sensor for La3+ ions based on N-[hexahydrocyclopentapyrol-2((1H)yl)amino]carbonyl]-4-methyl benzene sulfonamide (gliclazide) as a novel carrier was prepared. The electrode exhibits a Nernstian response for La3+ over a wide concentration range (1.0×10−1–1.0×10−6 M) with a slope of 20.1 mV per decade. The limit of detection is 8.0×10−7 M. The sensor has a very short response time (<15 s) and a useful working pH range of 4.0–8.0. The proposed membrane sensor shows excellent discriminating ability towards La3+ ions with regard to several alkali, alkaline earth, transition and heavy metal ions. The electrode was successfully applied for determination of La3+ in binary mixtures. [Copyright &y& Elsevier]