Publications by authors named "Serkan Emik"

5 Publications

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Design and fabrication of a semi-transparent solar cell considering the effect of the layer thickness of MoO/Ag/MoO transparent top contact on optical and electrical properties.

Sci Rep 2021 Jun 22;11(1):13079. Epub 2021 Jun 22.

Photonics Application and Research Center, Gazi University, 06500, Ankara, Turkey.

We conducted the present study to design and manufacture a semi-transparent organic solar cell (ST-OSC). First, we formed a transparent top contact as MoO/Ag/MoO in a dielectric/metal/dielectric (DMD) structure. We performed the production of an FTO/ZnO/P3HT:PCBM/MoO/Ag/MoO ST-OSC by integrating MoO/Ag/MoO (10/[Formula: see text]/[Formula: see text] nm) instead of an Ag electrode in an opaque FTO/ZnO/P3HT:PCBM/MoO/Ag (-/40/130/10/100 nm) OSC, after theoretically achieving optimal values of optical and electrical parameters depending on Ag layer thickness. The transparency decreased with the increase of [Formula: see text] values for current DMD. Meanwhile, maximum transmittance and average visible transmittance (AVT) indicated the maximum values of over 92% for [Formula: see text] = 4 and 8 nm, respectively. For ST-OSCs, the absorption and reflectance increased in the visible region by a wavelength of longer than 560 nm and in the whole near-infrared region by increasing [Formula: see text] up to 16 nm. Moreover, in the CIE chromaticity diagram, we reported a shift towards the D65 Planckian locus for colour coordinates of current ST-OSCs. Electrical analysis indicated the photogenerated current density and AVT values for [Formula: see text] nm as 63.30 mA/cm and 38.52%, respectively. Thus, the theoretical and experimental comparison of optical and electrical characteristics confirmed that the manufactured structure is potentially conducive for a high-performance ST-OSC.
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http://dx.doi.org/10.1038/s41598-021-92539-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8219690PMC
June 2021

Design of an amphiphilic hyperbranched core/shell-type polymeric nanocarrier platform for drug delivery.

Turk J Chem 2020 1;44(2):518-534. Epub 2020 Apr 1.

Department of Pharmaceutical Technology, Faculty of Pharmacy, Marmara University, İstanbul Turkey.

An amphiphilic core/shell-type polymer-based drug carrier system (HPAE- PCL-b -MPEG), composed of hyperbranched poly(aminoester)-based polymer (HPAE) as the core building block and poly(ethylene glycol)-b - poly(ε-caprolactone) diblock polymers (MPEG-b -PCL) as the shell building block, was designed. The synthesized polymers were characterized with FTIR, 1 H NMR, 13 C NMR, and GPC analysis. Monodisperse HPAE-PCL-b - MPEG nanoparticles with dimensions of < 200 nm and polydispersity index of < 0.5 were prepared by nanoprecipitation method and characterized with SEM, particle size, and zeta potential analysis. 5-Fluorouracil was encapsulated within HPAE-PCL-b -MPEG nanoparticles. In vitro drug release profiles and cytotoxicity of blank and 5-fluorouracil-loaded nanoparticles were examined against the human colon cancer HCT116 cell line. All results suggest that HPAE-PCL-b - MPEG nanoparticles offer an alternative and effective drug nanocarrier system for drug delivery applications.
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http://dx.doi.org/10.3906/kim-1910-35DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7671224PMC
April 2020

Targeted delivery of lacosamide-conjugated gold nanoparticles into the brain in temporal lobe epilepsy in rats.

Life Sci 2020 Sep 11;257:118081. Epub 2020 Jul 11.

Department of Physiology, School of Medicine, Koç University, Istanbul, Turkey. Electronic address:

Temporal lobe epilepsy (TLE) is the most common form of epilepsy with focal seizures, and currently available drugs may fail to provide a thorough treatment of the patients. The present study demonstrates the utility of glucose-coated gold nanoparticles (GNPs) as selective carriers of an antiepileptic drug, lacosamide (LCM), in developing a strategy to cross the blood-brain barrier to overcome drug resistance. Intravenous administration of LCM-loaded GNPs to epileptic animals yielded significantly higher nanoparticle levels in the hippocampus compared to the nanoparticle administration to intact animals. The amplitude and frequency of EEG-waves in both ictal and interictal stages decreased significantly after LCM-GNP administration to animals with TLE, while a decrease in the number of seizures was also observed though statistically insignificant. In these animals, malondialdehyde was unaffected, and glutathione levels were lower in the hippocampus compared to sham. Ultrastructurally, LCM-GNPs were observed in the brain parenchyma after intravenous injection to animals with TLE. We conclude that glucose-coated GNPs can be efficient in transferring effective doses of LCM into the brain enabling elimination of the need to administer high doses of the drug, and hence, may represent a new approach in the treatment of drug-resistant TLE.
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http://dx.doi.org/10.1016/j.lfs.2020.118081DOI Listing
September 2020

Folic acid-modified methotrexate-conjugated gold nanoparticles as nano-sized trojans for drug delivery to folate receptor-positive cancer cells.

Nanotechnology 2020 Aug 15;31(35):355101. Epub 2020 May 15.

Department of Chemical Engineering, Faculty of Engineering, Istanbul University-Cerrahpaşa, Avcılar 34320, Istanbul, Turkey.

Methotrexate (MTX), an analog of folic acid (FA), is a drug widely used in cancer treatment. To prevent its potential toxicity and enhance therapeutic efficacy, targeted drug delivery systems, especially nanotechnology-folate platforms, are a central strategy. Gold nanoparticles (AuNPs) are promising candidates to be used as drug delivery systems because of their small particle sizes and their inertness for the body. In this study, glutathione (GSH)-coated FA-modified spherical AuNPs (5.6 nm) were successfully synthesized, and the anticancer activity of novel MTX-loaded (MTX/Au-GSH-FA) NPs (11 nm) was examined. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) results showed that MTX/AuNPs possess spherical morphology, nanoscaled particle size, narrow size distribution, and good stability. In vitro studies showed that cytotoxicity of MTX/Au-GSH-FA to folate receptor-positive (FR+) human brain (U-87 MG) and cervical (HeLa) cancer cells enhanced significantly (∼3 and ∼10 fold, respectively) compared to free MTX while there was no significant effect in FR-negative human cell lines A549 (lung carcinoma), PC3 (prostate carcinoma), HEK-293 (healthy embryonic kidney). Moreover, the receptor specificity of the conjugate was shown by fluorescent microscopic imaging. In conclusion, these results indicate that the synthesized novel MTX/Au-GSH-FA NP complex seems to be a good candidate for effective and targeted delivery in FR+ cancer therapy.
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http://dx.doi.org/10.1088/1361-6528/ab9395DOI Listing
August 2020

A facile polymerisation of magnetic coal to enhanced phosphate removal from solution.

J Environ Manage 2019 Oct 26;247:356-362. Epub 2019 Jun 26.

Department of Civil and Environmental Engineering Syracuse University, NY, USA.

Globally, there are increased threats to available freshwater resources due to pollution, climate change, and increased demand from population growth. Phosphorus is one of the essential nutrients required for animal and plant growth. However, when it is released into freshwater resources in excess amounts, it can become a pollutant through eutrophication. This study aimed to enhance the removal of phosphate from water using modified coal. The coal was magnetised by in-situ synthesis using a precipitation technique. To obtain functional groups and mechanical stability, magnetised coal particles were coated with polyaniline, via the polymerisation of aniline to form Magnetised Unburnt Coal Polyaniline (MUC-PANI). The properties of MUC-PANI were investigated using TGA, BET, XRD, Raman spectroscopy, SEM, and FTIR. TGA reviewed MUC-PANI as 58% magnetised coal and 42% polyaniline, while the specific surface area increased from 30.0 to 42.2 m/g after modification. SEM indicated a cauliflower structure on the surface of MUC-PANI due to the successful polymerisation of polyaniline. The FTIR spectrum showed successful adsorption of phosphate due to the formation of incipient peak at1008 cm. The adsorption kinetic data are better fitted to the Elovich model. The Langmuir adsorption capacity of MUC-PANI is 147.1 mg PO/g at 25 °C and pH 5.0 (initial concentration 10-200 mg/L, dose 0.8 g/L). MUC-PANI is a cost-efficient compound for removal of phosphate because it is made from readily available coal.
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http://dx.doi.org/10.1016/j.jenvman.2019.06.088DOI Listing
October 2019
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