Selective Photokilling of Human Pancreatic Cancer Cells Using Cetuximab-Targeted Mesoporous Silica Nanoparticles for Delivery of Zinc Phthalocyanine

Background: Photodynamic therapy (PDT) is a non-invasive and innovative cancer therapy based on the photodynamic effect. In this study, we sought to determine the singlet oxygen production, intracellular uptake, and in vitro photodynamic therapy potential of Cetixumab-targeted, zinc(II) 2,3,9,10,16,17,23,24-octa(tert-butylphenoxy))phthalocyaninato(2-)-N29,N30,N31,N32 (ZnPcOBP)- loaded mesoporous silica nanoparticles against pancreatic cancer cells. Results: The quantum yield (Φ∆) value of ZnPcOBP was found to be 0.60 in toluene. In vitro cellular studies were performed to determine the dark- and phototoxicity of samples with various concentrations of ZnPcOBP by using pancreatic cells (AsPC-1, PANC-1 and MIA PaCa-2) and 20, 30, and 40 J/cm2 light fluences. No dark toxicity was observed for any sample in any cell line. ZnPcOBP alone showed a modest photodynamic activity. However, when incorporated in silica nanoparticles, it showed a relatively high phototoxic effect, which was further enhanced by Cetuximab, a monoclonal antibody that targets the Epidermal Growth Factor Receptor (EGFR). The cell-line dependent photokilling observed correlates well with EGFR expression levels in these cells. Conclusions: Imidazole-capped Cetuximab-targeted mesoporous silica nanoparticles are excellent vehicles for the selective delivery of ZnPcOBP to pancreatic cancer cells expressing the EGFR receptor. The novel nanosystem appears to be a suitable agent for photodynamic therapy of pancreatic tumor

Synthesis, Characterization and Thermal Degradation Kinetics of Polyazomethineester

A new polyester containing diimine ring, poly(imino isophthaloyl imino (glyoxal bis(2-methyl-4-hydroxy phenyl)imin)) poly[IPIGI] was synthesized by an Interfacial polycondensation reaction. The structure of poly[IPIGI] was confirmed by FT-IR and solid state 13C NMR techniques. The thermal stability was tested by TG-DTA and solubility was also studied. The kinetics of the thermal degradation of poly[IPIGI] was investigated by thermogravimetric analysis at different heating rates. TG curves showed that the thermal decomposition of poly[IPIGI] occurred in two stages. The apparent activation energies of thermal decomposition for poly[IPIGI], as determined by the Tang method (TM), the Flynn-Wall-Ozawa method (FWD), the Kissenger-Akahira-Sunose method (KAS) and the Coats-Redfern method (CR) are 74.8, 75.2, 76.5 and 83.9 kJ mol-1 for the first stage decomposition and 143.1, 143.7, 147.0 and 156.2 kJ mol-1 for the second stage decomposition, respectively. The mechanisms of each stage decomposition were also investigated by master plots

Synthesis of novel ruthenium II phenanthroline complex and its application to TiO2 and ZnO nanoparticles on the electrode of dye sensitized solar cells

WOS: 000335609600023Novel ruthenium (II) phenanthroline complex, Ru-II(4,4 ',4"-tri-tert-butyl-2,2 ':6 ',2"-terpyridine)-(4,7-dipheny1-1,10-phenanthroline-disulfonic acid disodium salt)(thiocyanate), [Ru(L1)(L2)(NCS)], [K328] was designed and synthesized as a photosensitizer for the dye sensitized solar cells (DSSCs) using TiO2 and ZnO electrodes. The density functional theory (DFT) calculation was used to estimate the photovoltaic properties of the complex in the design stage. In this paper, our aim was to investigate the interaction between semiconductor and anchoring groups like sulfonate group that binds onto TiO2 and ZnO surface. The influence of the semiconductor type on the performance of TiO2 and ZnO based photovoltaics has been tested. The solar cell performance of TiO2 based solar cell shows better efficiencies compared to ZnO based solar cell. Although sulfonate group did offer stronger binding onto the semiconductor surface, this does not help to improve cell performance for ZnO based solar cells. (C) 2014 Elsevier Ltd. All rights reserved.Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK); Alexander von Humboldt Foundation (AvH)Alexander von Humboldt Foundation; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)We acknowledge financial support from the Scientific and Technological Research Council of Turkey, TUBITAK and to Alexander von Humboldt Foundation (AvH). We thank Mechanical Engineer MSc. Cagatay Ela for illustrating figures and his fruitful help

Separation and preconcentration of Pb(II) using ionic liquid-modified silica and its determination by flame atomic absorption spectrometry

A new method based on microcolumn packed with ionic liquid-modified silica combined with flame atomic absorption spectrometry has been developed for the determination of lead in environmental samples. Several factors influencing the preconcentration efficiency of lead and its subsequent determination, such as pH of the sample, flow rate, mass of ionic liquid, and interfering effect, have been investigated. Lead could be quantitatively retained by ionic liquid-modified silica in the pH range of 5-7, and then eluted completely with 3.0 mL 1.0 mol L-1 HCl. The detection limit of this method for lead was 0.7 mu g L-1 with preconcentration factor of 185, and the relative standard deviation (RSD) was 4.2% at 0.1 mu g mL(-1) Pb(II). This method has been applied for the determination of trace amount of lead in NIST standard reference material 2709 (San Joaquin Soil) and river water samples with satisfactory results. (c) 2011 Published by Elsevier B.V

Separation and preconcentration of mercury in water samples by ionic liquid supported cloud point extraction and fluorimetric determination

We have developed a cloud point extraction procedure based on room temperature ionic liquid for the preconcentration and determination of mercury in water samples. Mercury ion was quantitatively extracted with tetraethyleneglycol-bis(3-methylimidazolium) diiodide in the form of its complex with 5,10,15,20-tetra-(4-phenoxyphenyl)porphyrin. The complex was back extracted from the room temperature ionic liquid phase into an aqueous media prior to its analysis by spectrofluorimetry. An overall preconcentration factor of 45 was accomplished upon preconcentration of a 20 mL sample. The limit of detection obtained under the optimal conditions is 0.08 mu g mL(-1), and the relative standard deviation for 10 replicate assays (at 0.5 g mL(-1) of Hg) was 2.4%. The method was successfully applied to the determination of mercury in tap, river and mineral water samples

Synthesis, characterization, electrochemical and spectroscopic studies of two new heteroleptic Ru(II) polypyridyl complexes

WOS: 000247195800020New [Ru(L1)(H(2)dcbpy)(NCS)(2)] [K30] and [Ru(L2)(H(2)dcbpy)(NCS)(2]) [K27] complexes were synthesized in a one-pot reaction starting from [RuCl2(p-cymene)](2), where the ligands (H2dcbpy = 4,4'-dicarboxy-2,2'-bipyridine, L1 = 4,5-diazafluoren-9-one, and L2 = 1, 10-phenanthroline-5,6-dione) are introduced sequentially. The resulting complexes were characterized by UV-vis, emission, IR, TGA, NMR, elemental analysis and cyclic voltammetry. The absorption and emission maxima of the two complexes are very similar to one another. The low-energy MLCT absorption maxima of the complexes appear at 524 nm, and the luminescence consists of a single band with a maximum at 700 and 720 nm, respectively, in DMF solution at 298 K. The electrochemical behaviors of the complexes have been studied in CH3CN by cyclic voltammetry. The LUMO energy levels of K27 and K30 were determined as -4.01 and -3.86 eV, respectively. The thermogravimetric analyses (TGA) of the prepared complexes show that the dyes are stable up to about 220 degrees C. Photodecompositions of the complexes in solution were studied in both ethanol and DMF solvents with a steady-state spectrofluori meter in time-based mode. The photostability of the compounds in DMF was found to increase twice in comparison to ethanol. Fluorescence quenching experiments of the one simple derivative of PDIs (N,N'-bis(I-ethylpropyl)perylene-3,4,9,10-tetracarboxylic acid (EP-PDI)) in DMF were studied vs. increasing K27 and K30 concentrations to monitor donor/acceptor capability. The rate constants (k(q)) of EP-PDI for each complex, K27 and K30, were determined as 7.72 x 10(12) and 6.52 x 10(12) M-1 s(-1), respectively. In addition, the free energies of exothermic photo-electron transfer (ET) processes between EP-PDI and complexes K27 and K30 were calculated to be -62.3 and -57.9 kcal mol(-1), respectively. (C) 2006 Elsevier Ltd. All rights reserved

The first application of water-soluble ruthenium phenanthroline complex for dye sensitized solar cells from aqueous solution using PEDOT:PSS counter electrode versus platinum counter electrode

WOS: 000324223200037Photovoltaic properties of Ru-II(4,7-diphenyl-1,10-phenanthroline-disulfonic acid disodium salt)-bis(2,2'-bipyridine), [Ru(L1)(bpy)(2)](PF6)(2), [K403] related to its adsorption behaviour onto the nanoporous titanium oxide are investigated in association with its water-soluble structure thanks to disulfonic acid disodium salt groups. Dye sensitized solar cell is fabricated from aqueous solution of water-soluble ruthenium complex. Devices are fabricated in a sandwich geometry using PEDOT:PSS counter electrode versus platinum counter electrode. Poly(3,4-ethylendioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) is coated on FTO conducting glass substrate by spin coating process and used as dye sensitized solar cell's counter electrode. Our device performance results show that PEDOT:PSS counter electrode in DSSC has reasonably good catalytic activity and can be used instead of platinum counter electrode. The energy conversion efficiency is significantly favourable for DSSC using PEDOT:PSS counter electrode. The optical and electrochemical behaviours of K403 are studied. Also cyclic voltammograms and estimated by density functional theory studies (DFT) are studied for calculating E-Homo and E-Lumo energy levels of ruthenium complex. (C) 2013 Elsevier B.V. All rights reserved.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110M803, 112M809]; Alexander von Humboldt Foundation (AvH)Alexander von Humboldt FoundationWe acknowledge financial support from The Scientific and Technological Research Council of Turkey (TUBITAK) (Grants: 110M803 and 112M809) in the framework of European Science Foundation (ESF-EUROCORES-EuroSolarFuels-10-FP-006), and Alexander von Humboldt Foundation (AvH). I thank to MSc. Cagatay ELA for his unending support and valuable advices