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Öğe Decellularization of bovine spinal cord meninges via supercritical CO2 and evaluating the extracellular matrix performance for neural tissue engineering applications(Mary Ann Liebert, Inc, 2024) Kurt, Tuğçe; Özüdoğru, Eren; Cengiz, Uğur; Derkuş, B.; Arslan, Yavuz Emre[No abstract available]Öğe 3D HYDROGELS FROM DETERGENT-FREE DECELLULARIZED SPINAL CORD MENINGES REINFORCED WITH HYDROPHILIC SILK FIBROIN FOR REGENERATIVE MEDICINE APPLICATIONS(Mary Ann Liebert, Inc, 2024) Kurt, Tuğçe; Arslan, Yavuz Emre[No abstract available]Öğe Early and sensitive diagnosis of celiac autoimmune disease by using carboxylic acid functionalized magnetic nanoparticles-assisted biosensing platform(Springer Wien, 2025) Aydın, Elif Burcu; Aydın, Muhammet; Sezgintürk, Mustafa KemalA novel impedimetric magneto-immunosensor based on iron oxide (Fe3O4) nanoparticles coated with 3-phosphonopropionic acid (3-PPA) (functionalized magnetic beads, or FMBs) was created for the highly sensitive and selective detection of anti-tissue transglutaminase antibody (anti-tTG) in human serum. This label-less immunosensor was introduced by magnetically attaching FMBs onto the working electrode surface with a neodium magnet. The FMBs were utilized as a sensing interface and had carboxylic acid groups for tTG molecules, which could selectively link the target anti-tTG antibody. The FMBs modification steps were carried out in microcentrifuge tubes and concentrated with magnetic force before electrochemical analyses. The specific immuno-interactions on the FMBs surface were characterized by using the electrochemical and microscopic techniques, and in the presence of anti-tTG antibodies, they were captured by tTG-immobilized magnetic beads, and significant increases were observed in impedimetric response. The magneto biosensor response was linearly related to the anti-tTG antibody level in a broad linear range of 0.125-15.62 U/mL and a low detection limit (LOD) of 0.04 U/mL. Additionally, this magneto sensor was stable, repeatable, reproducible, selective, and sensitive for determination of the anti-tTG. The commercial enzyme-linked immunosorbent assay (ELISA) method was employed to compare the responses of the suggested immunosensor in actual samples. The magneto biosensor results were in good agreement with the ELISA reference technique results. Consequently, the biosensor performance in the analysis of serum samples was acceptable.Öğe Tannic acid-based bio-MOFs with antibacterial and antioxidant properties acquiring non-hemolytic and non-cytotoxic characteristics(Elsevier, 2025) Şahiner, Nurettin; Güven, Olgun; Demirci, Şahin; Sağbaş Suner, Selin; Şahiner, Mehtap; Arı, Betül; Can, MehmetTannic acid (TA) based bio-metal phenolic networks (bio-MPNs) were prepared by using Cu(II), Zn(II), Bi(III), Ce(III), La(III), and Ti(IV) metal ions. TA-based bio-MPNs exhibited wedge-shaped pores between 16.4 and 25.8 nm pore size ranges. The higher gravimetric yield% was achieved for TA-Bi(III), and TA-Ti(IV) bio-MPNs with more than 90 %, and higher surface area was observed for TA-La(IIII) bio-MPNs as 56.2 m(2)/g with 17.3 nm average pore sizes. All TA-based MPNs are non-hemolytic with less than 5 % hemolysis ratio, whereas TA-based Bio-MPNs do not affect blood clotting with > 90 % blood clotting indexes except for TA-Cu(II) Bio-MPNs at 0.1 mg/mL concentration. Moreover, TA-Bi(III) and TA-Ce(III) Bio-MPNs were found to be safer materials showing no significant toxicity on L929 fibroblast cells at 100 mu g/mL concentration, along with TA-based Bio-MPNs prepared with Cu(II), Zn(II), La(III), and Ti(IV) metal ions that could be safely used in in vivo applications at 1 mu g/mL concentration. It has been proven by 2 different antioxidant tests that the prepared TA-based Bio-MPNs show antioxidant properties even if their TA-derived antioxidant properties decrease. Furthermore, all types of TA-based Bio-MPNs show great antimicrobial activity depending on the metal ion or microorganism types and the highest antibacterial/antifungal effect was determined for TA-Cu(II), and TA-Zn(II) Bio-MPNs with the lowest MBC/MFC values against Pseudomonas aeruginosa ATCC 10145, Bacillus subtilis ATCC 6633, and Candida albicans ATCC 10231.Öğe A novel and mass-sensitive quartz tuning fork platform for glial fibrillary acidic protein determination(Elsevier, 2025) Özcan, Burcu; Uludağ, İnci; Ünal, Mehmet Altay; Arı, Fikret; Sezgintürk, Mustafa Kemal; Özkan, Sibel A.Traumatic brain injury (TBI) is a major cause of mortality and disability worldwide, and its diagnosis is still difficult. A unique blood biomarker for numerous neurological disorders, including traumatic brain injury, is glial fibrillary acidic protein (GFAP). Portable, quick, and functional equipments are crucial in fighting against neurological illnesses. Quartz Tuning Fork (QTF) biosensors are attracting great attention due to their seamless integration with miniaturized and portable devices. This study introduces a new, adaptable, affordable frequency analyzer for GFAP detection. A simple and stable process to design a QTF system which has gold surface modified with 3-mercaptopropionic acid (3-MPA) and its biocompatibility with GFAP antigen was investigated. The surface morphology of the QTF system was analyzed during its immobilization procedure using Atomic Force Microscopy (AFM). The constructed QTF sensor system demonstrated high repeatability (the standard deviation: +/- 0.12183 Hz), good reproducibility, linearity, ability to detect antigen concentrations at femtogram levels. It proved that the QTF sensor system decorated with 3-MPA could be a good choice for the sensitive determination of GFAP, according to the statistical data. The modified QTF sensor demonstrated remarkably straightforward and mass-sensitive GFAP detection. The developed QTF-based biosensor achieved an outstanding linear detection range of 1-100 fg mL-1. The responses of the designed QTF-based sensor to commercial human serum also show that it is a successful and promising system for clinical use.Öğe Celiac disease biomarker quantification in human fluid microenvironment: A selective and ultrasensitive magnetosensing immunoplatform(Elsevier Science Sa, 2025) Aydın, Elif Burcu; Aydın, Muhammet; Sezgintürk, Mustafa KemalAn innovative magnetosensing strategy for highly sensitive impedimetric determination of anti-tissue transglutaminase antibodies (anti-tTG) was developed and applied successfully in real serum and saliva samples. The transducer surface of the proposed immunosensor consisted of an indium tin electrode (ITO) attached with poly (3-thienylacetic acid) (PTAc)-coated magnetic nanoparticles, which provided a very useful surface for the attachment of the biological molecules. The PTAc-coated magnetic nanoparticles were held by a magnetic field on the electrode surface, and the immunological reaction was carried out on magnetic nanoparticles as a solid platform on which the tissue transglutaminase (tTG) was covalently bound. With the specific capture of anti-tTG on the tTG-immobilized surface, an impedimetric signal was measured, and the electrochemical response of this specific reaction was correlated with the anti-tTG concentration. A linear relationship between the impedimetric signal and the anti-tTG concentration was obtained over a wide range of 0.125-25 U/mL. This magnetobiosensor illustrated a stable quantitative signal to anti-tTG concentrations after 45 minutes of incubation with a limit of detection of 0.034 U/mL and a low relative standard deviation (RSD) of 3.61 %, n = 3. This immunosensor's electrochemical behaviour was thoroughly examined, with consideration given to factors including sensitivity, specificity, repeatability, reproducibility, and storage stability. Lastly, serum and saliva samples were analyzed using the biosensor, and excellent correlation was achieved between the commercial ELISA kit and the proposed immunosensor. As a result, this approach held out a lot of hope for a straightforward, affordable, and user-friendly analytical technique that would enable the label-free measurement of anti-tTG levels.Öğe MIP-based sensing strategies for the diagnosis of prostate and lung cancers(Elsevier, 2025) Uludağ Anıl, İnci; Sezgintürk, Mustafa KemalProstate and lung cancer are among the most prevalent and lethal forms of the disease, and, globally, cancer is a primary cause of mortality. Early diagnosis and the application of precise biomarkers are crucial for prolonging patient lifespan and enhancing quality of life. Molecularly imprinted polymers (MIPs) are synthetic substances capable of selectively identifying and binding specific target molecules. Besides their sensitivity to biomolecules, MIPs offer significant advantages in cancer biomarker detection due to their cost-effectiveness and flexible architectures. MIP-based biosensors designed for the detection of prostate and lung cancer-specific biomarkers provide unique solutions that enhance the diagnostic process and improve its accuracy. This study aims to assess the present state of MIP-based biosensors in the detection of biomarkers for prostate and lung cancer, as well as the potential opportunities provided by this technology. This study will present an overview of potential biomarkers for lung and prostate cancer, clarify the fundamental features of MIPs, and discuss their uses in MIPbased biosensors along with prospective future applications. In this context, our review is aimed to contribute to the development of innovative methods used in early cancer diagnosis.Öğe Nanoparticles for Biomedical Use Derived from Natural Biomolecules: Tannic Acid and Arginine(MDPI, 2025) Şahiner, Mehtap; Sağbas Suner, Selin; Şahiner, NurettinBackground/Objectives: Tannic acid (TA) is a well-known natural phenolic acid composed of ten gallic acids linked to each other with ester bonding possessing excellent antioxidant properties in addition to antimicrobial and anticancer characteristics. Arginine (ARG) is a positively charged amino acid at physiological pH because of nitrogen-rich side chain. Method: Here, poly(tannic acid-co-arginine) (p(TA-co-ARG)) particles at three mole ratios, TA:ARG = 1:1, 1:2, and 1:3, were prepared via a Mannich condensation reaction between TA and ARG by utilizing formaldehyde as a linking agent. Results: The p(TA-co-ARG) particles in 300-1000 nm size range with smooth surfaces visualized via SEM analysis were attained. Abundant numbers of functional groups, -OH, -NH2, and -COOH stemming from TA and ARG constituent confirmed by FT-IR analysis. The isoelectric point (IEP) of the particles increased from pH 4.98 to pH 7.30 by increasing the ARG ratios in p(TA-co-ARG) particles. The antioxidant capacity of p(TA-co-ARG) particles via gallic acid (GA) and rosmarinic acid (RA) equivalents tests revealed that particles possess concentration-dependent antioxidant potency and increased by TA content. The alpha-glucosidase inhibition of p(TA-co-ARG) particles (2 mg/mL) 1:1 and 1:2 mole ratios revealed significant enzyme inhibition ability, e.g., 91.3 +/- 3.1% and 77.6 +/- 12.0%. Interestingly, p(TA-co-ARG) (1:3 ratio) possessed significant antibacterial effectiveness against Escherichia coli (ATCC 8739) and Staphylococcus aureus (ATCC 6538) bacteria. Furthermore, all p(TA-co-ARG) particles at 1000 mg/mL concentration showed >80% toxicity on L929 fibroblast cells and increased as ARG content of p(TA-co-ARG) particles is increased. Conclusions: p(TA-co-ARG) showed significant potential as natural biomaterials for biomedical use.Öğe Natural Molecule-Derived Nanogels from Hematoxylin and l-lysine for Biomedical Use with Antimicrobial Properties(MDPI, 2025) Şahiner, Mehtap; Tian, Zhi; Allen-Gipson, Diane; Sunol, Aydın K.; Şahiner, NurettinHematoxylin (HT) is a natural staining dye used in histopathology, often combined with Eosin for H&E staining. A poly(hematoxylin-co-l-lysine) (p(HT-co-l)) nanonetwork was synthesized through a one-step Mannich condensation reaction using formaldehyde as a linking agent. The resulting p(HT-co-l) nanogels had an average size of about 200 nm and exhibited a smooth surface and desirable functional groups such as -OH, -NH2, and -COOH, as recognized by FT-IR analysis. The isoelectric point (IEP) of the p(HT-co-l) nanogel was determined as pH 7.9, close to physiological environments, despite HT being acidic IEP at pH 1.7 and l-lysine being basic IPE at pH 8.7. The time-dependent swelling studies of p(HT-co-l) nanogels were carried out using dynamic light scattering (DLS) in different salt solutions, e.g., MgCl2, KNO3, KCl, PBS, and DI water environments revealed that nanogels have high swelling ability depending on the medium, e.g., >10-fold in a saline solution compared to distilled water within 1.5 h. Hydrolytic degradation studies in PBS demonstrated a linear release profile up to 125 h at 37.5 degrees C. The p(HT-co-l) nanogels also demonstrated significant antimicrobial and antifungal activities against E. coli (ATCC 8739), S. aureus (ATCC 6538), and C. albicans (ATCC 10231). Furthermore, biocompatibility tests indicated that p(HT-co-l) nanogels are more biocompatible than HT alone, as tested with human Nuli-1 bronchial epithelial cells.Öğe AChE Inhibition Capability of Nanogels Derived from Natural Molecules: Tannic Acid and Lysine for Alzheimer's Disease(MDPI, 2025) Şahiner, Mehtap; Sağbaş Suner, Selin; Şahiner, NurettinBackground/Objectives: Tannic acid (TA), a known natural polyphenolic acid with many bioactivities including antioxidants, antibacterial, and antiviral, can be combined with a natural essential amino acid L-lysine (LYS) in nanogel formulations to produce p(TA-co-LYS) (p(TA-co-LYS)) nanogels. Methods: A 1:1 mole ratio of TA:LYS was used to prepare corresponding spherical nanogels employing formaldehyde as a linker via the Mannich reaction. Results: The attained p(TA-co-LYS) particles were in 283 +/- 57 nm size ranges (via SEM analysis) and possessed smooth surfaces. The zeta potential measurements of p(TA-co-LYS) nanogels suspension at different solution pHs revealed the isoelectric point (IEP) of pH 4.9, suggesting that the particles are negatively charged at the physiological pH range (e.g., at 7.4). In addition to the antioxidant efficacy of nanogels confirmed by three different tests, p(TA-co-LYS) particles showed significant Fe(II) ion chelating capacity at 350 mu g/mL concentrations compared to bare TA, which is 21%, whereas the LYS molecule had a chelating capacity of 100% at the same concentrations. Moreover, it was found that p(TA-co-LYS) nanogels inhibited the Acetylcholinesterase enzyme (AChE) at a concentration-dependent profile, e.g., at 333 mu g/mL concentration of p(TA-co-LYS), 57.2% of the enzyme AChE activity was inhibited. Furthermore, the minimum inhibition concentrations of p(TA-co-LYS) nanogels of Gram-negative Escherichia coli (ATCC 8739) and Gram-positive Staphylococcus aureus (ATCC 6538) were determined as 12.5 mg/mL. Conclusions: As cytotoxicity studies of p(TA-co-LYS) nanogels on L929 fibroblast cells also ascertained that these particles can be safely used in many biomedical applications, including antioxidant materials, drug delivery devices, and enzyme inhibitors.Öğe Toxicity Evaluation of Sulfobetainized Branched Polyethyleneimine via Antibacterial and Biocompatibility Assays(MDPI, 2025) Şahiner, Mehtap; Sağbaş Suner, Selin; Demirci, Şahin; Ayyala, Ramesh S.; Şahiner, NurettinBranched polyethyleneimine (PEI), possessing different types of amines-e.g., primary, secondary, and tertiary-in the polymer chains are well known for their antibacterial properties and DNA condensing ability, affording substantial advantages in many biomedical uses, including gene therapy. However, because of PEI's toxicity, depending on the molecular weight, its widespread biomedical use is hindered. Therefore, in this study, PEIs with different molecular weights-i.e., 600, 1200, and 1800 g/mol-were modified with 1,3-propane sultone, undergoing a sulfobetainization reaction in a single step to attain a zwitterionic structure: sulfobetainized PEI (b-PEI). The sulfobetainization reaction was carried out twice to increase the zwitterionic repeating unit on PEI chains. The increasing number of SO3- groups on the PEI chains was confirmed by the increased peak intensities around 1160 and 1035 cm-1 on the FT-IR spectrum, which are assigned to symmetric and asymmetric S=O peaks. The elemental analysis results for first- and second- betainization PEIs, abbreviated as b1-PEI and b2-PEI, respectively, were revealedthe increased wt% of S confirming the successful multiple-sulfobetainization of the PEI chains. Thermal stability analyses of PEIs and their corresponding multiple-sulfobetainized forms showed that multiple-sulfobetainization reactions increased the thermal stability of bare PEI chains. PEIs with lower molecular weights exhibited more antimicrobial properties. As PEI is sulfobetainated, its antimicrobial properties can be further adjusted via sulfobetainization (once or twice), or by adjusting the corresponding solution pH, or by protonating them with different acids with different counter anions. The cell toxicity of PEI on L929 fibroblast cells was slightly increased by increasing the molecular weight of the PEI, but all forms of sulfobetainized PEIs were found to be safe (no toxicity), even at 1000 mu g/mL concentrations.Öğe Effect of synthesis conditions on cristobalite crystallization in low-cost ceramic membranes(Korean Assoc Crystal Growth, Inc, 2025) Zeren, Nevzat; Abalı, SerkanThe raw materials quartz, calcite, kaolin, and zeolite were used to fabricate /f-cristobalite-based ceramic membranes at low temperatures. The raw materials were divided into two groups: calcite and zeolite. Calcite and zeolite raw material mixtures were prepared in different proportions by weight. Quartz-calcite-kaolin and quartz-zeolite-kaolin raw material mixtures were subjected to grinding, drying and shaping processes and then sintered separately at temperatures of 1100 degrees C, 1150 degrees C, and 1200 degrees C in a 7-hour furnace regime. All samples were subjected to X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), density, and mechanical testing. The effects of various raw materials with different compositions and sintering temperatures on the characteristics of ceramic membranes were examined. The necessary conditions for sufficient cristobalite production were created by a sintering temperature of 1200 degrees C with zeolite as the raw material. These criteria are also suitable for homogeneous pore size distribution and crystal structure formation. The flexural strength of the membrane containing 10 wt.% zeolite sintered at 1200 degrees C was 34.75 N.mm-2. The average pore diameter of the membrane sintered at 1200 degrees C with an initial zeolite content of 25 wt.%, was 33.95 nm.Öğe An innovative and mass-sensitive quartz tuning fork (QTF) biosensor for GFAP detection: A novel approach for traumatic brain injury diagnosis(Elsevier Ltd, 2025) Özcan, Burcu; Uludağ Anıl, İnci; Ünal, Mehmet Altay; Arı, Fikret; Sezgintürk, Mustafa Kemal; Özkan, Sibel AyşılThe early diagnosis and management of traumatic brain injury (TBI) are dependent upon the early and precise detection of glial fibrillary acidic protein (GFAP). In this investigation, a novel biosensor based on quartz tuning forks (QTF) was introduced and functionalized with 11-mercaptoundecanoic acid (11-MUA). This biosensor is designed to facilitate the highly sensitive and selective detection of GFAP in human serum. In contrast to conventional neuroimaging methods, which are resource-intensive and frequently inaccessible in emergency situations, this innovative biosensor offers a portable, cost-effective, and efficient alternative for rapid GFAP measurement. The detection range of the system is 0.05 fg mL−1 to 25 fg mL−1. The Atomic Force Microscopy (AFM) was utilized to visualize the morphology of the QTF surface during the immobilization steps of the sensor. The developed biosensor presented advantages such as ability to determine GFAP concentrations at femtogram level, reproducibility and repeatability (standard deviation: ±0.0935966 Hz, and coefficient of variation: 7.91 %). This study highlights a significant progression in biosensing technology, providing an exceptionally sensitive and scalable platform for diagnosing neurological disorders, with potential uses in point-of-care environments. © 2025 The AuthorsÖğe A promising disposable biosensor for diagnosis of Rheumatoid Arthritis disease(Springer Nature, 2025) Uzman, Ecem; Sezgintürk, Mustafa KemalRheumatoid Arthritis (RA) is a chronic autoimmune inflammatory disease that causes joint damage. Recently, Anti-citrullinated protein antibodies (ACPA) have been accepted as biomarkers for the diagnosis of RA due to their high specificity. This study aims to develop an immunosensor for the detection of mutated citrullinated vimentin antibody (MCV), which is autoantibody in the pathophysiology of RA from the ACPA family. For this purpose, (3-Aminopropil) trietoksisilan (3-APTES) silane agent was used to form a self-assembled monolayer (SAM) on the indium tin oxide coated polyethylene terephthalate (ITO-PET) electrode due to its sensitivity, practicality and ease of use. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measurement techniques were used in the immobilization, optimization and characterization stages and real commercial serum samples were tested for the reliability of the immunosensor. This analysis method is the first biosensor based system for the determination of MCV. By the developed immunosensor, the determination range was obtained as 0.01 pg/mL -50 pg/mL MCV with a LOD value of 7 × 10–4 pg/mL MCV. As a result, a reproducible, specific and sensitive immunosensor was fabricated. © Qatar University and Springer Nature Switzerland AG 2024.Öğe Preparation of composite hydrogels containing fly ash as low-cost adsorbent material and its use in dye adsorption(Springer Science and Business Media Deutschland GmbH, 2022) Önder, Alper; Ilgın, Pınar; Özay, Hava; Özay, ÖzgürAbstract: Recycling industrial wastes is necessary for the economy and the environment. Additionally, it is important to develop high-efficiency adsorbents to prevent severe water pollution caused by wastewater containing dye agents. Here, poly(2-acrylamido-2-methylpropane sulfonic acid)-fly ash composite hydrogel was synthesized with a variety of fly ash proportions with the radical polymerization method. The synthesized composite hydrogel was used for adsorption of methylene blue and methyl orange dyes from water containing dye agents. A variety of parameters such as initial dye concentration, solution pH, anion effects, temperature, contact time and adsorbent amount were investigated for optimization of the adsorption process. The poly(2-acrylamido-2-methylpropane sulfonic acid)-fly ash composite hydrogel was determined to be an effective adsorbent to remove both the cationic dye methylene blue (1438.68 mg g−1) and the anionic dye methyl orange (646.54 mg g−1). Experimental adsorption data were assessed with a variety of isotherm and kinetic models. It was determined that the adsorption of both dye molecules abided by the pseudo-second-order kinetic model. The thermodynamic parameters were determined as ΔH° = − 15.77 ± 5.22 kJ mol−1, ΔS = − 45.05 ± 16.42 J mol−1 K−1 and ΔG° < 0 for MB, ΔH° = − 20.13 ± 4.83 kJ mol−1, ΔS = − 72.87 ± 15.20 J mol−1 K−1 and ΔG° > 0 for MO. In conclusion, a material was synthesized that can be used as a single adsorbent composite material for both anionic and cationic dyes. In addition to the perfect adsorption capacity of this material, it offers reusability and a broad area of application for a variety of dye agents.Öğe Super Porous Carboxymethyl Cellulose–Tannic Acid (TA@CMC) Cryogels with Antioxidant, Antibacterial, and α-Glucosidase Enzyme Inhibition Abilities(Mdpi, 2024) Şahiner, Mehtap; Demirci, Şahin; Şahiner, NurettinHere, super porous carboxymethyl cellulose (CMC) cryogels were synthesized in 10-100% crosslinker and the presence of TA, at varying amounts of TA, e.g., 10 and 25 wt% of CMC under cryogenic conditions (-20 degrees C) as TA@CMCs. To control the degradation of CMC cryogel networks, the crosslinking ratio of divinyl sulfone (DVS:X) to CMC varied at 10, 25, 50, and 100% moles of the CMC repeating unit. Higher hydrolytic degradation was observed for CMC 10%X cryogels at pH 1.0 with 28.4 +/- 1.2% weight loss. On the other hand, the TA-release studies from TA@CMC-based cryogels showed that higher TA releases were observed for both TA@CMC 10% and 25% cryogels at pH 7.4, with 23.6 +/- 1.1, and 46.5 +/- 2.3 mg/g in 480 min, which are equal to almost 24% and 18% of the TA contents of the corresponding cryogels, respectively. The antioxidant properties of TA@CMC cryogels were examined, and worthy antioxidant properties were observed due to the TA. The alpha-glucosidase enzyme inhibition ability of the prepared cryogels was examined at different concentrations by grinding cryogels, and it was determined that TA@CMC 25% cryogel at 3 mg/mL concentration inhibited 70.4 + 1.3% of the enzyme. All bare CMC-based cryogels were found to be non-hemolytic with a less than 1% hemolysis ratio and also effective on the blood coagulation mechanism with blood-clotting index (BCI) values between 62.1 and 81.7% at 1 mg/mL concentrations. On the other hand, TA@CMC 25% cryogels exhibited a slight hemolytic profile with a 6.1 +/- 0.8% hemolysis ratio and did not affect the blood coagulation mechanism with 97.8 +/- 0.4% BCI value.Öğe Effect of deposition charges on the wettability performance of electrochromic polymers(Elsevier, 2015) Çağlar, Aysel; Cengiz, Uğur; Yıldırım, Mehmet; Kaya, İsmetElectrochromic polymers have been designed as future candidates for electrochromic displays (ECDs) and smart windows. This class of conducting polymers has been studied with their several optical properties as well as spectroelectrochemical stabilities. In practical use their contamination and abrasion could be expected to be main problem as exposed to moisture and other possible pollutants. In this study, we present a perspective to well-known electrochromic polymers in the words of their durable use. For this aim, a series of electrochromic polymers are deposited on indium tin oxide (ITO) coated glass plates by bulk electrolysis. Polymeric films are deposited by varied deposition charges (Q(s)) ranging from 62 to 620 mC cm(-2) for comparison. Equilibrium water contact angle (theta(equ)(water)) measurements of the prepared surfaces are measured by Attention Theta Optical Tensiometer. Surface roughness parameters (RMS) are determined by atomic force microscopy (AFM) technique and used for interpretation of hydrophobic-hydrophilic characteristics. The results clearly indicate that; poly(ethylenedioxythiophene) (PEDOT) has a hydrophilic surface whose hydrophilicity is increased by applied deposition charge and becomes a superhydrophile at high deposition charges. Among the tested polymers polycarbazole (PCarb) is the most promising long lifetime candidate due to its relatively hydrophobic character. Also, the hydrophobicity of PCarb is linearly increased by increasing deposition charge and reaches an optimum point at a particular condition. (C) 2015 Elsevier B.V. All rights reserved.Öğe Polydopamine Coating of Graphitic Carbon Nitride, g-C3N4, Improves Biomedical Application(Mdpi, 2024) Şahiner, Mehtap; Demirci, Şahin; Şahiner, NurettinGraphitic carbon nitride (g-C3N4) is an intriguing nanomaterial that exhibits photoconductive fluorescence properties under UV-visible light. Dopamine (DA) coating of g-C3N4 prepared from melamine was accomplished via self-polymerization of DA as polydopamine (PDA). The g-C3N4 was coated with PDA 1, 3, and 5 times repeatedly as (PDA@g-C3N4) in tris buffer at pH 8.5. As the number of PDA coatings was increased on g-C3N4, the peak intensity at 1512 cm(-1) for N-H bending increased. In addition, the increased weight loss values of PDA@g-C3N4 structures at 600 degrees C from TGA thermograms confirmed that the coating was accomplished. The band gap of g-C3N4, 2.72 eV, was reduced to 0.87 eV after five coatings with PDA. A pristine g-C3N4 was found to have an isoelectric point (IEP) of 4.0, whereas the isoelectric points of 1PDA@g-C3N4 and 3PDA@g-C3N4 are close to each other at 3.94 and 3.91, respectively. On the other hand, the IEP of 5PDA@g-C3N4 was determined at pH 5.75 assuming complete coating with g-C3N4. The biocompatibility of g-C3N4 and PDA@g-C3N4 against L929 fibroblast cell lines revealed that all PDA@g-C3N4 coatings were found to be biocompatible up to a 1000 mg/mL concentration, establishing that PDA coatings did not adversely affect the biocompatibility of the composite materials. In addition, PDA@g-C3N4 was screened for antioxidant potential via total phenol content (TPC) and total flavonoid content assays and it was found that PDA@g-C3N4 has recognizable TPC values and increased linearly with an increased number of PDA coatings. Furthermore, blood compatibility of pristine g-C3N4 is enhanced considerably upon PDA coating, affirmed by hemolysis and the blood clotting index%. Additionally, alpha-glucosidase inhibitory properties of PDA@g-C3N4 structures revealed that 67.6 + 9.8% of this enzyme was evenly inhibited by 3PDA@g-C3N4 structure.Öğe Bioengineered three-dimensional physical constructs from quince seed mucilage for human adipose-derived mesenchymal stem cells(Sage Publications Ltd, 2020) Şimşek, Ekin; Karaca, Burak; Arslan, Yavuz EmreIn this study, we aimed at fabricating a novel porous physical construct from quince seed mucilage for translational medicine applications. To achieve this goal, quince seed mucilage was extracted, molded, and freeze-dried. After being freeze-dried, the molded constructs were chemically crosslinked with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide to maintain the mechanical integrity of the structure. The fabricated scaffolds were characterized in-depth by scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, thermogravimetric analysis, and dynamic mechanical analysis in addition to the swelling, liquid uptake, and porosity tests. The extraction yield of mucilage was calculated to be 6.28% +/- 0.40% (n = 3). The swelling ratio of crosslinked quince seed mucilage-derived scaffolds was found to be 12,677.50% +/- 388.82% (n = 3), whereas the porosity of crosslinked quince seed mucilage-derived scaffolds was 83.43% +/- 2.84% (n = 3). The analyses confirmed the crosslinked quince seed mucilage-derived scaffolds to be possessed interconnected, highly porous structure. Afterward, human adipose-derived mesenchymal stem cells were seeded on the crosslinked quince seed mucilage-derived scaffolds, and the cell viability on the scaffolds was assessed with 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The MTT results revealed the scaffolds not to be possessed any cytotoxic effect on seeded cells. Human adipose-derived mesenchymal stem cells adhesion and migration on the crosslinked quince seed mucilage-derived scaffolds were also evaluated histologically using hematoxylin and eosin staining in addition to scanning electron microscopy analysis. In conclusion, we believe that crosslinked quince seed mucilage-derived scaffolds have the potential to be an alternative to routinely used polysaccharides in regenerative medicine applications.Öğe Nitrogen Doped Carbon-Dot Embedded Poly(lactic acid-co-glycolic acid) Composite Films for Potential Use in Food Packing Industry and Wound Dressing(Mdpi, 2022) Şahiner, Mehtap; Ari, Betül; Ram, Manoj K.; Şahiner, NurettinHere, nitrogen-doped carbon dots (N-doped CDs) were synthesized by the hydrothermal method embedded within poly(lactic acid-co-glycolic acid) ((PLGA)) films at different amounts. The N-doped CDs (or CD) that possess fluorescence properties also have antimicrobial properties against S. aureus and E. coli microorganisms, determined by the disc diffusion method with 19 +/- 2 and 18 +/- 1 mm zone diameters, respectively. The CD embedded PLGA films (CD@PLGA) with different CD contents revealed an increased fluorescence intensity with the increased amount of CD. Moreover, the antibacterial potency of 50% CD containing PLGA (50-CD@PLGA) films (by weight) against S. aureus and E. coli microorganisms was examined and the zone diameters were found to be 14 +/- 1 and 13 +/- 1 mm, respectively. In addition, CD release studies from different amounts of CD (2.5-50 by weight) containing composite films showed that 50-CD@PLGA film released 127 +/- 16 mg/g CD dots, which is 38 +/- 5% of the embedded CDs in about 12 days, suggesting their potential application in food packing and wound dressing. Moreover, all CD@PLGA films were found to be blood compatible via hemolysis and blood clotting index tests with 90% blood clotting indices regardless of their CD content.