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    Does the Addition of Poly(glycolide-co-lactide) to Teicoplanin-Containing Poly(methyl methacrylate) Beads Change the Elution Characteristics?
    (Springer Heidelberg, 2020) Kilinc, Seyran; Pazarci, Ozhan; Cakmak, Nese Keklikcioglu; Tas, Ayca
    Background The objective of our study was to measure and compare the elution characteristics of teicoplanin from poly(methyl methacrylate) PMMA beads with those of poly(glycolide-co-lactide) PGLA-added beads. Methods The study included two groups of PMMA + teicoplanin beads. PMMA was added to teicoplanin in Group 1 and PMMA + PGLA was added to teicoplanin in Group 2. A total of 16 beads of 1 cm(3) were created for each group. Samples were added individually to tubes containing 3 ml of phosphate-buffered saline (PBS). Antibiotic elution was measured by measuring absorbance values of 1-ml samples taken at regular intervals using a UV-Vis spectrophotometer and cumulative percentages of drug release were calculated. In addition, the spectra of teicoplanin were identified using a FTIR spectrophotometer in a wavelength range of 400-4000 cm(-1). Results Drug elution in the PBS medium was measured and compared for Groups 1 and 2. The cumulative percentage of drug release from the PGLA-added beads (Group 2) was significantly higher (p = 0.01). The molecular structure of teicoplanin was also confirmed using FTIR. Conclusion The in vitro results showed that the addition of biodegradable PGLA into bone cement functions as a water-soluble porogen which allows for significant increases in the elution of teicoplanin from cement. This increase in elution suggests that the PGLA would allow for further fluid contact and exchange with the previously entrapped drug. These results may have important clinical applications.
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    EXPERIMENTAL STUDY OF THERMAL CONDUCTIVITY OF BORIC ACID-WATER SOLUTIONS
    (Begell House Inc, 2019) Cakmak, Nese Keklikcioglu
    In this study, it was primarily aimed to prepare and examine the impacts of temperature and weight concentration on the thermophysical characteristics of boric acid-water solutions. Estimation of the boric acid structure was performed by SEM, FT-IR, XRD, and UV-Vis spectrophotometer. Then, homogeneous and stable aqueous boric acid was prepared with a probe sonicator at different weight concentrations. The impacts of boric acid concentration and temperature on thermal conductivity were examined. Thermal conductivity measurements show that boric acid-water solutions have higher thermal conductivity compared to water. There is a strong association between the improvement in thermal conductivity and the concentration of boric acid, and it increases along with the increase in loading. In case the loading of boric acid is 3.0 wt.%, the enhancement ratio is found as 3.95% at a temperature of 25 degrees C, and in case of the increase in temperature to 50 degrees C, the enhancement reaches 5.39%. Thus, the temperature in the temperature range measured determines the enhancement level.
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    PEGylated Titanium Dioxide Nanoparticle-bound Doxorubicin and Paclitaxel Drugs Affect Prostate Cancer Cells and Alter the Expression of DUSP Family Genes
    (Bentham Science Publ Ltd, 2025) Tuncbilek, Zuhal; Cakmak, Nese Keklikcioglu; Tas, Ayca; Ayan, Durmus; Silig, Yavuz
    Background PC is among the cancer types with high incidence and mortality. New and effective strategies are being sought for the treatment of deadly cancers, such as PC. In this context, the use of nanocarrier systems containing titanium dioxide can improve treatment outcomes and increase the effectiveness of anticancer drugs.Objective This study aimed to evaluate the cytotoxic activity of doxorubicin (DOX) and paclitaxel (PTX) drugs on the prostate cancer (PC) cell line by attaching them to pegylated titanium dioxide nanoparticles and to examine their effect on the expression levels of dual-specificity phosphatase (DUSP) genes.Methods Free DOX and PTX drugs, DOX and PTX compounds bound to the pegylated titanium dioxide system were applied to DU-145 cells, a PC cell line, under in vitro conditions, and MTT analysis was performed. Additionally, the IC50 values of these compounds were analyzed. In addition, the expression levels of DUSP1, DUSP2, DUSP4, DUSP6, and DUSP10 genes were measured using RT-PCR. Additionally, bioinformatics and molecular docking analyses were performed on DUSP proteins.Results The cytotoxic activity of PTX compound bound to PEGylated TiO2 was found to be higher than that of DOX compound bound to PEGylated TiO2. Additionally, when the expression levels were compared to the control group, the expression levels of DUSPs were found to be lower in the drugs of the drug carrier systems.Conclusion Accordingly, it was predicted that the pegylated titanium dioxide nano-based carrier could be effective in PC.
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    Preparation, characterization, stability, and thermal conductivity of rGO-Fe3O4-TiO2 hybrid nanofluid: An experimental study
    (Elsevier, 2020) Cakmak, Nese Keklikcioglu; Said, Zafar; Sundar, L. Syam; Ali, Ziad M.; Tiwari, Arun Kumar
    In the present study, ternary rGO-Fe3O4-TiO2 nanocomposites was produced using a straightforward sol-gel technique. The nanofluids are synthesized using rGO-Fe3O4-TiO2 hybrid nanoparticles suspended in ethylene glycol (EG). Ternary rGO-Fe3O4-TiO2 nanocomposite (0.01-0.25 mass. %) were dispersed in EG acquiring stable nanofluids. The ternary rGO-Fe3O4-TiO2 nanocomposite present in the colloidal phase has been categorized by MR, SEM, EDX, XRD, and Zeta potential. At varying temperatures between 25 and 60 degrees C, the thermal conductivity was explored. Experimental results show that the stability of all the studied rGO-Fe3O4-TiO2/EG nanofluid samples was above 52.04 mV. Enhancement in thermal conductivity for rGO-Fe3O4-TiO2/EG nanofluids significantly increases with mass concentration and temperature, with an enhancement of 133% at 60 degrees C for 0.25 wt%. The best R-2 coefficient of determination estimated at 25 degrees C, 30 degrees C, 40 degrees C. 50 degrees C, and 60 degrees C was 95.6%, 98.2%, 95.4%, 97.6%, and 99.0%. Therefore, the investigated ternary hybrid nanofluid can be utilized for both heating and cooling applications with long term stability. (C) 2020 Elsevier B.V. All rights reserved.
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    Synthesis, stability, density, viscosity of ethylene glycol-based ternary hybrid nanofluids: Experimental investigations and model -prediction using modern machine learning techniques
    (Elsevier, 2022) Said, Zafar; Cakmak, Nese Keklikcioglu; Sharma, Prabhakar; Sundar, L. Syam; Inayat, Abrar; Keklikcioglu, Orhan; Li, Changhe
    A direct sol-gel technique was utilized to produce rGO-Fe3O4-TiO2 ternary hybrid nanocomposites to produce ethylene glycol (EG) based stable nanofluids, characterized by energy-dispersive X-ray, X-ray dispersion, Fourier transform infrared spectroscopy, scanning electron microscopy, and zeta potential. Viscosity and density analysis were investigated by varying temperatures (25 to 50 & DEG;C), and wt% (0.01 to 0.25). For 0.25 wt% at 50 & DEG;C, density increased by 2.45%, and viscosity by 133.5%. The development of a prediction model by processing the variational parameters with machine learning and studying properties such as characterization, stability, and density of rGO-Fe3O4-TiO2 hybrid nanofluids has provided an unprecedented study in the literature. The nonlinear nature and volume of data generated by the subsequent experimental study were difficult to model using traditional analytical methods. As a result, for the creation of prognostic models, advanced machine learning techniques such as Boosted Regression Tree (BRT), Support Vector Machine (SVM), and Artificial Neural Networks (ANN) was applied. These prediction models' prognostic skills and uncertainty were assessed using statistical indices, Theil's statistics, and Taylor's diagram. The R-value for the BRT-based density (0.9989) and viscosity (0.9979) prediction models was higher than that of the ANN-based and SVM-based prediction models. In developed density models, Theil's U2 uncertainty was as low as 0.0689, 0.0775, and 0.0981 for BRT, ANN, and SVM, respectively. As a conclusion, it is stated that BRT, ANN, and SVM can accurately imitate the laboratory-based assessment of density and viscosity values of ternary hybrid nanofluids over a wide temperature and nanoparticle concentration ratio range. On the other hand, the BRT was marginally better than ANN but much better than SVM. The current study's findings are appropriate for applications needing long-term stability and improved heat transfer performance. (C)& nbsp;2022 Elsevier B.V. All rights reserved.
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    SYNTHESIZE AND STABILITY ANALYSIS OF PEGYLATED NANOGRAPHENE OXIDE FOR DELIVERY OF DOXORUBICIN
    (Serban Solacolu Foundation, 2019) Cakmak, Nese Keklikcioglu; Tezel, Guler Bengusu
    In this study, graphene oxide nanoparticle (NGO) was fabricated via modified Hummers' method and then modified with amine terminated 4-armed PEG to enhance the biocompatibility and stability of nano drug carrier. In our strategy, Doxorubicin (DOX) was used as a model drug. DOX loading onto NGO-PEG was synthesized by simply mixing with the NGO-PEG solution at pH 7 overnight. NGO, NGO-PEG and NGO-PEG-DOX was characterized by power X-ray diffraction, scanning electron microscopy, and UV spectroscopy. Stability analysis was performed with zeta potential. The experimental results showed that the zeta potential analysis values were above +/- 40 mV. NGO-PEG-DOX is still had very good dispersion stability even after 45 days. Therefore, this drug loaded product can be good candidate for treatment of cancer.
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    Use of magnetic nanoparticle loaded functionalized multi-walled carbon nanotubes for effective removal of Maxilon red GRL from aqueous solutions
    (Springer, 2025) Senturk, Ilknur; Cakmak, Nese Keklikcioglu
    In this study, acid-functionalized multi-walled carbon nanotubes (MWCNTs-COOH) were synthesized by subjecting them to acid treatment and subsequently incorporating magnetite (Fe3O4) nanoparticles onto their surface (MWCNTs-COOH/Fe3O4) through co-precipitating Fe2+ and Fe3+ in the MWCNTs-COOH colloidal suspension. These were then subjected to comprehensive characterization using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller surface area analysis (BET), and Vibrating sample magnetometer (VSM). The adsorption efficiency of the synthesized MWCNTs-COOH/Fe3O4 nanocomposite for the removal of Maxilon Red GRL dye (MR GRL) from aqueous solutions was examined under various conditions, including initial MR GRL concentration (50-250 mg/L), solution pH (2-12), adsorbent dose (0.1-1.0 g/L), and temperature (25-55 degrees C). Results indicated that the MWCNTs-COOH/Fe3O4 nanocomposites displayed strong adsorption capabilities for MR GRL in aqueous solutions, and the adsorption process adhered to the Langmuir isotherm model. Kinetic adsorption data were well-fitted to the pseudo-second-order model. At the natural pH of 5.8 and a temperature of 25 degrees C, the adsorption capacity and removal percentage were determined as 188.68 mg/g and 97%, respectively. The adsorption of MR GRL onto MWCNTs-COOH/Fe3O4 was endothermic and spontaneous, according to thermodynamic characteristics. These findings indicate the potential of the newly synthesized adsorbent in advancing water purification through effective adsorptive separation. [GRAPHICS]