Browsing by Author "Turk, Mustafa"

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Fabrication and Characterization of PVA/ODA-MMT-Poly(MA-Alt-1-Octadecene)-G-Graphene Oxide E-Spun Nanofiber Electrolytes and Their Response to Bone Cancer Cells
(2016) Rzayev, Zakir M. O.; Salimi, Kouroush; Bunyatova, Ulviya; Acar, Selim; Salamov, Bahtiyar; Turk, Mustafa; 26838849; J-5194-2019
This work presents a new approach to fabrication and characterization of novel polymer nanofiber electrolytes from intercalated PVA/ODA-MMT nanocomposite as a matrix polymer and encapsulated graphene oxide (GO) nanosheets with amphiphilic reactive copolymer as partner polymers using electrospinning method. The chemical and physical structures, surface morphology, thermal behaviors and electric conductivity of nanocomposites and nanofibers were investigated using analyses methods including FTIR, XRD, SEM, DSC-TGA and conductivity analysis. Significant improvements in nanofiber morphology and size distribution were observed when GO and reactive organoclay were incorporated as reinforcement fillers into various matrix/partner solution blends. The structural factors of matrix-partner polymer nanocomposite particles with higher zeta-potential play important roles in both chemical and physical interfacial interactions and phase separation processing and also lead to the formation of nanofibers with unique surface morphologies and good conductivities. The cytotoxic, necrotic and apoptotic effects of chosen nanofibers on osteocarcinoma cells were also investigated. These multifunctional, self-assembled, nanofibrous surfaces can serve as semi-conductive and bioactive platforms in various electrochemical and bio-engineering processes, as well as reactive matrices used for the immobilization of various biopolymer pfecursors. (C) 2015 Elsevier B.V. All rights reserved.
Novel Multifunctional Colloidal Carbohydrate Nanofiber Electrolytes with Excellent Conductivity and Responses to Bone Cancer Cells
(2015) Gokmen, Fatma Ozge; Rzayev, Zakir M. O.; Salimi, Kouroush; Bunyatova, Ulviya; Acar, Selim; Salamov, Bahtiyar; Turk, Mustafa; 26344321; J-5194-2019
This work presents a new approach to fabricating novel polymer nanofiber composites (NFCs) from water solution blends of PVA (hydrolyzed 89%)/ODA-MMT and Na-CMC/ODA-MMT nanocomposites as well as their folic acid (FA) incorporated modifications (NC-3-FA and NC-4-FA) through green electrospinning nanotechnology. The chemical and physical structures and surface morphology of the nanofiber composites were confirmed. Significant improvements in nanofiber morphology and size distribution of the NFC-3-FA and NFC-4-FA nanofibers with lower average means 110 and 113 nm compared with those of NFC-1/NFC-2 nanofibers (270 and 323 nm) were observed. The structural elements of polymer NFCs, particularly loaded partner NC-2, plays an important role in chemical and physical interfacial interactions, phase separation processing and enables the formation of nanofibers with unique morphology and excellent conductivity (NFC-3-FA 3.25 x 10(-9) S/cm and NFC-4-FA 8.33 x 10(-4) S/cm). This is attributed to the higher surface contact areas and multifunctional self-assembled supramacromolecular nanostructures of amorphous colloidal electrolytes. The anticancer activity of FA-containing nanofibers against osteocarcinoma cells were evaluated by cytotoxicity, apoptotic and necrotic analysis methods. (C) 2015 Elsevier Ltd. All rights reserved.
Transscleral Delivery of Bevacizumab-Loaded Chitosan Nanoparticles
(2019) Ugurlu, Nagihan; Asik, Mehmet Dogan; Cakmak, Hasan Basri; Tuncer, Sema; Turk, Mustafa; Cagil, Nurullah; Denkbas, Emir Baki; 30841975
Purpose: The aim of this study was to synthesize bevacizumab-loaded nanoparticles and evaluate their effects on the treatment of posterior segment diseases via subtenon injections. Methods: Bevacizumab-loaded chitosan nanoparticles (BLCNs) were synthesized by the ionic gelation method, and their physicochemical characteristics and in vitro release profile were studied. The BLCNs were characterized using atomic force microscopy (AFM), FTIR spectroscopy, dynamic light scattering, and scanning electron microscopy. The BLCNs were delivered into rabbits' eyes via posterior subtenon injections. An immunohistochemical evaluation of the ocular tissues was performed, and the vitreous humor and serum bevacizumab levels were measured by ELISA. Results: Bevacizumab-loaded chitosan nanoparticles with a diameter of 80 to 380 nm were prepared and characterized. In vitro studies showed that after the first 5 days of the experiment, a significant increase in the drug release maintained the desired drug dosage for 3 weeks. Immunohistochemical in vivo studies revealed that there were BLCNs penetrating through the sclera. Furthermore, the intravitreal bevacizumab concentration reached a maximum concentration of 18 mu g/ml, and it decreased to 6 mu g/ml after only a week. Conclusion: The results revealed that subtenon injection of BLCNs is a promising alternative to intravitreal injections. In addition to the ELISA studies, immunohistochemical experiments confirmed that BLCNs enable transscleral bevacizumab penetration, and BLCN usage may provide the required bevacizumab levels for the treatment of posterior segment diseases.