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Öğe A digital image analysis study on the disintegration kinetics of reticular fibers in the ethylene glycol-induced rat liver tissue(Wiley, 2020) Saraydin, Serpil Unver; Saraydin, Dursun; Sahin Inan, Zeynep DenizEthylene glycol (EG), the raw material of polyethylenterephthalate, which is the most consumed plastic in the world, has low toxicity, but its metabolites are toxic. EG metabolites can cause acidosis, fibrosis, and eventually cirrhosis in the liver. This study aimed to investigate the effect of EG on rat liver and to determine the quantitative values of the disintegration of reticular fibers (RF) in the liver with the dose duration and to investigate the changes by digital image analysis (DIA). For this purpose, Wistar albino rats were divided into control, and five different daily experimental groups. The control group received saline, and the experimental groups received EG. At the end of experiments, liver tissues of all euthanized rats were removed, and sections were taken, and RF was shown by silver staining. It was observed that the RF fragments in the experimental groups were less than the control group. DIA of RF fragments was then performed with Olympus cellSensDimension 1.15 software and number, area, and ROI% values of the fragments were determined. Statistical analysis revealed that there was a significant difference between control and all experimental groups. RF fragments showed first-order disintegration kinetics, mean disintegration rate constant, and half-time values were 0.1 day(-1)and 7 days, respectively. Consequently, the digital image analysis approach can be a useful tool for the biologist, pathologist, fibrosis-cirrhosis specialist, and computer scientist to understand the effects of toxic chemicals in the liver and analyze reticular fiber disintegration.Öğe A study of digital image analysis on the acrylamide derivative monomers induced apoptosis in rat cerebrum(Wiley, 2020) Saraydin, Serpil Unver; Saraydin, Dursun; Nan, Zeynep Deniz SahinNowadays, apoptosis is mostly evaluated visually in histological studies. By using the quantitative digital image analysis, this study aimed to investigate the effect of acrylamide-based monomers (acrylamide [AAm], methacrylamide [MAAm], N-isopropylacrylamide [NIPAm]) on the cerebrum tissues in rats, which are the most common water-soluble monomers in the production of polymeric hydrogels used as biomaterials. The Wistar albino rats weighing similar to 220-240 g were divided into control and three test groups. The control group received 1 mL of saline, and the test groups received 1 mL of aqueous 50 mg/kg/day intramuscular injection of AAm, MAAm, and NIPAm, respectively. At the end of the experiments, brain tissues of all rats euthanized by intramuscular injection of sodium pentobarbital were removed. Terminal deoxynucleotide transferase dUTP nick and labeling (TUNEL) method was applied to brain tissue sections. The monomers have been shown to cause apoptosis due to oxidative stress in cerebrum tissue. Based on apoptosis by tunneling method, quantitative digital image analysis of cell fragments was performed with Olympus cellSens Dimension 1.15 software, and the number, total count area, selected area, average area, and ROI% values of the fragments were found. In addition, the total area and ROI% values of the fragments increased linearly with increasing the molar mass of monomers from the digital image analysis data. Quantitative digital image analysis can facilitate the monitoring of apoptosis caused by the oxidative stress of monomers used in the production of the biomaterials.Öğe Acrylamide-Sepiolite Based Composite Hydrogels for Immobilization of Invertase(WILEY, 2009) Oztop, H. Nursevin; Hepokur, Ceylan; Saraydin, DursunNovel composite hydrogels, poly(acrylamide)-sepiolite (PAS), poly(acrylamide/acrylic acid)-sepiolite (PAAS), and poly(acrylamide/itaconic acid)-sepiolite (PAIS) were prepared and used for the immobilization of invertase. The parameters of equilibrium swelling, diffusional exponent, and diffusion coefficient of these hydrogels were calculated from swelling experiments. Invertase was immobilized onto PAS, PAAS, and PAIS and immobilized invertases (PASI, PAASI, and PAISI) were prepared. Optimum pH values for free invertase, PASI, PAASI, and PAISI are found to be 5, 5.5, 4.5, and 6, respectively, and the optimum temperatures were 30, 50, 50, and 35 degrees C for free invertase PASI, PAASI, and PAISI. It was found that K-m values of free invertase, PASI, PAASI, and PAISI were 11.3, 41.0, 94.5, and 56.0 mM, respectively. V-max values were 2 mu mol/min for free invertase, 8.10 mu mol/min for PASI, 1.30 mu mol/min for PAASI, and 0.42 mu mol/min for PAISI, respectively. The invertase immobilized hydrogels showed excellent, temperature, storage, and operational stability.Öğe Adsorption of phenazine dyes using poly(hydroxamic acid) hydrogels from aqueous solutions(WILEY, 2018) Saraydin, Dursun; Isikver, Yasemin; Karadag, ErdenerSwelling and adsorption properties of poly(hydroxamic acid), (PHA) hydrogels in aqueous solutions of some phenazine dyes such as Neutral Red, Safranin T, and Janus Green have been investigated. PHA hydrogels containing N,N methylenebisacrylamide or ethyleneglycoldimethacrylate were used in experiments on swelling, diffusion and adsorption of the dyes. The equilibrium swelling (S-eq) values of PHA hydrogels in aqueous solutions of the phenazine dyes were calculated as 2.16-33.25 g g(-1). Swelling kinetic parameters such as initial swelling rate, swelling rate constant, and maximum swelling were found. Dye diffusion into hydrogels was found to be non-Fickian in character. Diffusion coefficients are ranged 1.32 x 10(-6) cm(2) s(-1) - 44.70 x 10(-6) cm(2) s(-1). Adsorption of the phenazine dyes onto PHA hydrogels was studied by batch technique. PHA hydrogels in the phenazine dye solutions showed the dark coloration. The data was found that Freundlich isotherm model fits. According the Freundlich constants, the adsorption isotherms are of S-type in Giles classification. All swelling and binding parameters for PHA-EGDMA were found to be higher than those for PHA-NNMBA. The type of crosslinker influenced the swelling, binding, and sorption more than the type of dye. Finally, it can be said that PHA hydrogels may be used a sorbent for removal of dyes. POLYM. ENG. SCI., 58:310-318, 2018. (c) 2017 Society of Plastics EngineersÖğe An Experimental and Computational Evaluation of the Interaction Between Intelligent Ampholyte Acrylamide/Acrylic Acid/2-(Acryloyloxy)ethyl Trimethylammonium Chloride Hydrogel and Dyes(Springer, 2024) Isikver, Yasemin; Saraydin, Dursun; Karakus, NihatNovel intelligent ampholyte hydrogel (IAH) was prepared by a free radical solution redox polymerization of acrylamide, acrylic acid, 2-(acryloyloxy)ethyl trimethylammonium chloride as monomers, and ethylene glycol dimethacrylate as crosslinker. Spectroscopic, thermal, and surface properties of IAH were performed using ATR/FTIR, molecular electrostatic potential maps, TGA and DSC. Swelling studies were performed at increasing pH and temperature. IAH has been identified as intelligent and ampholyte. Cavity sizes of IAH were calculated from SEM photographs by digital image analysis method. Due to the large cavities of IAH, this hydrogel was used for dye sorption. The binding of carminic acid to IAH was L-type according to the Giles classification system, while crystal violet and methyl violet were S-type. Binding parameters of dyes such as binding constant, monolayer coverage, and maximum fractional occupancy were calculated from the Langmuir model or Saraydin model. It was observed that the binding between the dyes used and the IAH was realized by electrostatic interaction, and the hydrogen bonds in the carminic acid increased this bonding. This study could be a pioneering model for the preparation of potential and effective intelligent ampholyte hydrogels for the removal of both anionic and cationic dyes from aquatic environments by electrostatic interaction/H-bonding.Öğe Bio-based Iota-Carrageenan-g-(acrylamide-co-maleic Acid) Smart Graft Hydrogels with Different Crosslinkers and Their Interaction with Uranyl Ions(Springer, 2024) Isikver, Yasemin; Saraydin, Dursun; Sarikaya, cagla NurIn this study, novel smart graft hydrogels (SGHs) were prepared by simultaneous grafting/crosslinking of acrylamide and maleic acid onto iota-carrageenan (CR) in the presence of N,N '-methylenebisacrylamide or 1,4-butanediol diacrylate crosslinkers. The SGHs were characterized by FTIR, SEM, TG, DSC analysis and swelling studies. The sizes of the cavities in the SGHs were determined by digital image analysis using micrographs from the SEM. The average cavity diameters in SGHs are around 10 to 12 mu m and have a heterogeneous distribution. The adsorption of uranyl ion on SGHs was investigated by spectroscopic, kinetic and equilibrium studies. The accuracy of the pseudo-first and pseudo-second-order kinetic models applied to the swelling and adsorption properties of the hydrogels were evaluated by correlation coefficient (R2), mean bias error (MBE), root mean square error (RMSE), reduced chi-square (chi 2) and t-statistic model. The swelling and adsorption kinetics of the hydrogels were found to be consistent with the pseudo-second-order model. The adsorption isotherms of uranyl ion on SGHs were found to be L-type according to the Giles isotherm classification. Freundlich and Langmuir models were applied to these isotherms and adsorption parameters were calculated. From the Langmuir model, the monolayer adsorption capacities of SGH-N and SGH-B were calculated to be 162 and 167 mg g-1, and the maximum fractional occupancy values were calculated to be 99% and 97%, respectively. The pH-responsive swelling and adsorption behavior of the hydrogels was determined and the transition points were determined by applying Saraydin's model to the plotted curves. It was also observed that the amount of uranyl ions adsorbed increased with the increase of adsorbent mass. In conclusion, this study demonstrates that the synthesized SGHs can be used as an effective adsorbent for the removal of uranyl ions from an aqueous solution.Öğe Cationic dye adsorption by acrylamide/itaconic acid hydrogels in aqueous solutions(John Wiley and Sons Ltd, 1997) Karada?, Erdener; Saraydin, Dursun; Güven, OlgunAcrylamide/itaconic acid (AAm/IA) hydrogels containing different quantities of itaconic acid have been irradiated with ? radiation. The hydrogels were used in an experiment concerning the adsorption of cationic dyes such as Basic Blue 9, Basic Violet 1 and Basic Blue 12. In the experiments of the adsorption of dyes from their synthetic aqueous solutions, type S adsorption isotherms were found. One mole of monomeric unit of AAm/IA hydrogels adsorbed 78.5-513.1 ?mole of Basic Blue 9, 60.2-641.1 ?mole of Basic Violet 1 and, 28.8-593.3 ?mole of Basic Blue 12, while acrylamide hydrogel did not adsorb any cationic dye. As a result, it was shown that the AAm/IA hydrogels could be used as an adsorbent for water pollutants such as dyes, and immobilization of these organic contaminants in the hydrogels from waste water can solve one of the most important environmental problems of the textile industry. © 1997 by John Wiley & Sons, Ltd.Öğe The Effects of Monomers Used in Polymeric Biomaterials on Renal Tissue(SOC CHILENA ANATOMIA, 2017) Saraydin, Serpil Unver; Saraydin, Dursun; Inan, Zeynep Deniz Sahin; Kutlu, Berna OzdenogluBiomaterials are mostly polymers and are used in artificial organ production in contemporary medicine. They are prepared by the polymerization reaction of many monomers. There are many monomers used in biomaterial production. In this study, we investigated whether acrylamide (AAm), methacrylamide (MAAm), N-isopropylacrylamide (NIPAm) and acrylic acid (AAc) used in polymeric biomaterial production had histopathological effects on renal tissue. In the present study, Wistar albino rats weighing similar to 250-300 g were used. Following the intramuscular injections of 1 mL aqueous monomer solutions at 50 mg/kg concentrations, acrylamide group animals were sacrificed at 1st, 2nd and 3rd weeks, the other monomer group animals were sacrificed at 1st, 2nd, 4th and 6th weeks. One mL serum physiologic were injected intramuscularly to the control group animals at the same time intervals with the experimental group animals. After histological follow-up, serial sections were prepared for evaluation under light microscope. In addition, the diameters of glomeruli and glomeruli space (Bowman's space) are measured, and the changes of the values of all groups with the exposure time were investigated. Acrylamide and its derivatives cause glomerular, arteriolar and tubule interstitial damage in the renal tissue. The narrowing glomeruli space, increasing diffuse mesangial matrix and tubular dilation was observed in some groups. In addition, dilatation, dissociation of tubular epithelium, thickening basement membranes and glycogenic vacuolization was also noted. These adverse results may be due to residual monomer. There should be no monomer residue in the polymer used as biomaterials.Öğe Environmentally Sensitive Hydrogels: N-isopropyl acrylamide/Acrylamide/Mono-, Di-, Tricarboxylic Acid Crosslinked Polymers(WILEY-BLACKWELL, 2015) Isikver, Yasemin; Saraydin, DursunEnvironmentally sensitive hydrogels responsive to various stimuli such as temperature, pH, ionic strength of the medium and the solvent were prepared by using N-isopropyl acrylamide (NIPAM), acrylamide (AAm) and monomers that have various number of carboxylic acid (XA) functionality using N,N-methylene bisacrylamide (Bis) as crosslinker. Hydrogels were prepared via free radical polymerization reaction in aqueous solution. P(NIPAAm-co-AAm) and p(NIPAAm-co-AAm)/XA hydrogels that contain monoprotic crotonic acid (CA) exhibit a lover critical solution temperature (LCST) at 28 degrees C, whereas p(NIPAAm-co-AAm)/IA (IA:itaconic acid), and P(NIPAAm-co-AAm)/ACA (ACA:acotonic acid) hydrogels exhibit a lover critical solution temperature at 30.7 degrees C and 34.4 degrees C, respectively. Spectroscopic and thermal analyses were performed for the structural and thermal characterizations of the prepared hydrogel. The swelling experiments as equilibrium swelling percentages by gravimetrically were carried out in different solvents, at different solutions temperature, pH, and ionic strengths to determine their effects on swelling characteristic of hydrogels. POLYM. ENG. SCI., 55:843-851, 2015. (c) 2014 Society of Plastics EngineersÖğe Evaluation of the Cytotoxic effects of various monomers In vitro also their effects on Apoptosis and GFAP immunolocalization in rat spinal cord In vivo(DRUNPP-SARAJEVO, 2011) Saraydin, Serpil Unver; Bulut, H. Eray; Ozum, Unal; Inan, Z. Deniz Sahin; Polat, Zubeyde Akin; Yalman, Yucel; Saraydin, DursunBiomaterials are mostly polymers made by monomers, and are used in artificial organ production in contemporary medicine. They are prepared by the polimerization reaction of certain monomers. The aim of the present study was to investigate whether acrylamide, methacrylamide, N-isopropylacrylamid, acrylic acid, 2-hydroxyethyl methacrylat, 1-vinyl-2-pyrrolidone and ethylene glycol had cytotoxic effects and induce apoptosis or not in spinal cord. Immunolocalization of glial fibrillary acidic protein (GFAP) was also determined, and it was evaluated by using semi-quantitative morphometrical techniques. The cellular process of apoptosis is an important component of tissue and organ development as well as the natural response to disease and injury. Therefore the positive immunohistochemical staining for apoptosis was also examined by TUNEL staining technique. Following the intramuscular injection of aqueous monomer solutions that are prepared in certain concentration, appropriate tissue samples obtained at certain time intervals were fixed in 10% buffered neutral formaline. The cytotoxicity of monomers on cultured fibroblastic cell lines was examined in vitro. Acrylic acid had the most cytotoxic effect when compared to the methacrylamide and the ethylene glycol groups. GFAP immunoreactivity was found to be rather stronger in the methacrylamide than the other monomers application groups. TUNEL positive cell were observed in the methacrylamide, acrylic acid, N-vynil pyrrolidine, acrylamide, N-isopropylacrilamid and 2-hydroxyethyl metacrylad application groups than the other groups. In conclusion, while some monomers used in biomaterial production seemed not to affect the cell viability and GFAP immunoreactivity, some other monomers had adverse effects on those features. This in turn may contribute to the pathological changes associated to the monomer type.Öğe Full Factorial Design Approach to Hg(II) Adsorption onto Hydrogels(SPRINGER HEIDELBERG, 2015) Bingol, Deniz; Saraydin, Dursun; Ozbay, Dilek SolpanA 2(4) factorial design was used to evaluate the quantitative adsorption of Hg(II) ions in an aqueous solution onto radiation crosslinked poly(acrylic acid/acrylamide) hydrogels. The influence on the binding ratio (r) of variables such as pH, temperature, initial concentration of solution, and material was analyzed statistically using a suggested regression equation. The results demonstrate that the initial concentration of Hg(II) is the most significant parameter. A maximum Hg(II) ion uptake of 15.50 mg/g (with standard deviation, 0.20) was achieved at a high initial Hg(II) concentration (100 mg/L), low pH (2.5), and low temperature (15 A degrees C) for both of radiation crosslinked poly(AAm-co-AAc) hydrogel samples in a significance level of 5%.Öğe Histopatological Effect Characteristics of Various Biomaterials and Monomers Used in Polymeric Biomaterial Production(INTECH EUROPE, 2011) Saraydin, Serpil Unver; Saraydin, Dursun; Pignatello, R…Öğe Immobilization of catalase onto chitosan and cibacron blue F3GA attached chitosan beads(ELSEVIER SCIENCE INC, 2007) Cetinus, Senay Akkus; Oztop, H. Nursevin; Saraydin, DursunIn this study, chitosan beads (Ch-bead) and cibacron blue F3GA attached chitosan beads (CB-Ch-bead) were prepared. Their characteristics were investigated with experiments of swelling, thermogravimetric analysis and Fourier transform infrared (FTIR) spectroscopic analysis. Catalase (CAT) was immobilized onto these beads. The adsorption isotherms have a Langmuirian shape for Ch-beads and CB-Ch-beads. The CAT adsorption capacity of Ch-beads is higher than that of CB-Ch-beads, but CB-Ch-CAT showed better activity according to the Ch-CAT. The values of apparent &, were found to be 18 and 41 mM for Ch-CAT and CB-Ch-CAT, respectively. However, V-max values were calculated as 4800 and 14,250 mu mol (mg protein)(-1) min(-1) for Ch-CAT and CB-Ch-CAT, respectively. Furthermore, various characteristics of immobilized catalase, such as the temperature profile, thermal stability, optimum pH, operational stability and storage stability were evaluated. Optimum temperature and optimum pH values were found as 35 degrees C and 7.0 for maximum activity of Ch-CAT and CB-Ch-CAT. It was observed that thermal, storage and operational stabilities of the enzyme were increased with immobilization. (c) 2007 Elsevier Inc. All rights reserved.Öğe In vitro swelling studies in simulated physiological solutions and biocompatibility of NIPAM-based hydrogels with some biochemical parameters of human sera(TAYLOR & FRANCIS INC, 2017) Isikver, Yasemin; Saraydin, Dursun; Aydin, HuseyinIn modern medicine, commonly used biomaterials originating from metals, ceramics and polymers have shown biocompatibility with blood, tissues, cells, etc., in the human body. Polymeric biomaterials are usually understood as polymeric materials and articles made from them which are used in medicine, biotechnology biomedicine, bioengineering, pharmaceutical, veterinary, food industry, agriculture and related fields. In this in vitro study, swellings and the biocompatibility of environmentally sensitive N-isopropyl acrylamide-based (ES) hydrogels such as N-isopropyl acrylamide/acrylamide (ES/0), and N-isopropyl acrylamide/acrylamide/ carboxylic acids (ES/XAc) prepared by free radical polymerization in aqueous solutions has been investigated. Selected carboxylic acids for this study were acrylic, methacrylic, crotonic, itaconic, maleic, mesaconic and aconitic acid. The equilibrium swelling of the hydrogels are investigated in simulated physiological fluids or crystalloid solutions such as HCl-KCl buffer (pH = 1.1), universal buffer (pH = 5.5), phosphate buffer (pH = 7.4), urea, isotonic NaCl, isotonic KCl, 5% dextrose, 5% dextrose+isotonic NaCl, Ringer's lactate, human blood serum and human serum albumin solution at 37 degrees C. For the analysis of biocompatibility, ES hydrogels are incubated in 5 different human sera and their biocompatibilities with some biochemical parameters have been investigated for 24h at 37 degrees C. No significant differences in values before and after the test procedures have been found. It is therefore concluded that environmentally sensitive N-isopropyl acrylamide-based hydrogels are biocompatible for biochemical parameters of human sera.Öğe INFLUENCE OF CONCENTRATIONS OF METHACRYLATE AND ACRYLATE MONOMERS ON THE PROPERTIES OF FIBER REINFORCED POLYMETHYL METHACRYLATE DENTURE BASE MATERIALS(DE GRUYTER POLAND SP ZOO, 2018) Tugut, Faik; Turgut, Mehmet; Saraydin, DursunThe study aimed to evaluate the effects of adding different concentrations of 2 hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), ethyl methacrylate (EA) and isobutyl methacrylate (IBMA) monomers on the structural, thermal and mechanical properties of a fiber reinforced heat-polymerized acrylic resin. For each test, 126 acrylic resin specimens were fabricated and divided into 6 groups with 7 specimens each. One group was the control group, the other one is a fiber reinforced group and others were the test groups, which were formed according to the different concentrations of monomers. 6 mm length, and the weight ratio of 3% short glass fibers are added to acrylic powder polymerized by heating. The 2%, 5%, 10%, at 20 % ratios of different comonomers added to a monomer of MMA are composed of copolymer structures. Flexural strength was assessed with a three-point bending test using a universal testing machine. Impact strength testing was conducted using an impact test machine by the Charpy method. The analysis of the connection between acrylic resin and fiber by SEM and structural changes in the acrylic resin was investigated by FTIR spectroscopy. Data analyses using analysis of Kruskal-Wallis and Mann-Whitney U tests (alpha=0.05) significant difference tests showed that adding 2%, 5% HEMA and IBMA monomers significantly increased the flexural and impact strength compared to the control, only fiber and others group (P<0.05). It is observed that the process of adding low concentration of HEMA and IBMA monomers improved certain mechanical properties of fiber reinforced with polymethylmethacrylate.Öğe Interaction of some cationic dyes with acrylamide/itaconic acid hydrogels(John Wiley and Sons Inc., 1996) Karada?, Erdener; Saraydin, Dursun; Güven, OlgunAcrylamide/itaconic acid (AAm/IA) hydrogels prepared by irradiating with ? radiation were used in experiments on uptake of some cationic dyes such as union green B (UG-B), basic blue 17 (BB-17), basic red 2 (BR-2), and lauths violet (LV). Adsorption of the cationic dyes onto AAm/IA hydrogels is studied by batch adsorption technique at 25°C. In the experiments of the adsorption, Langmiur type adsorption in the Giles classification system was found. Some binding and thermodynamic parameters for AAm/IA hydrogel-dye systems were calculated by using Klotz method. Adsorption studies indicated that monolayer coverages of AAm/IA hydrogel by these dyes were increased with following order BB-17 > UG-B > BR-2 > LV. © 1996 John Wiley & Sons, Inc.Öğe Interpenetrating polymeric network hydrogels for potential gastrointestinal drug release(JOHN WILEY & SONS LTD, 2007) Ekici, Sema; Saraydin, DursunNew interpenetrating polymeric network (IPN) hydrogels based on chitosan (C), poly(N-vinyl pyrrolidone) (PVP) and poly(acrylic acid) (PAAc), crosslinked with glutaraldchyde (G) and N,N'-methylenebisacrylamide (MBA), were prepared and investigated for potential gastrointestinal drug delivery vehicles utilizing a model drug, amoxicillin. IPN hydrogels were synthesized by simultaneous polymerization/crosslinking of acrylic acid monomer in the presence of another polymer (C) and crosslinker (G, MBA). Three different concentrations of glutaraldehyde were used (0.5, 1.0 and 2.0 w/w) to control the overall porosity of the hydrogels, named C-P-AAc/0.5, C-P-AAc/1.0 and C-P-AAc/2.0, respectively. Spectroscopic and thermal analyses such as Fourier transform infrared spectroscopy, thermogravimetric analysis and thermornechanical analysis were performed for IPN characterization. Equilibrium swelling studies were conducted for pH and temperature response behavior. Swelling studies were also carried out in simulated gastric fluid of pH = 1.1 and simulated intestinal fluid of pH = 7.4 to investigate possible site-specific drug delivery. It was found that the release behavior of the drug from these IPN hydrogels was dependent on the pH of the medium and the proportion of crosslinker in the IPN. It was observed that amoxicillin release at pH = 7.4 was higher than at pH = 1.1. The analysis of the drug release showed that amoxicillin was released from these hydrogels through a non-Fickian diffusion mechanism. (c) 2007 Society of Chemical Industry.Öğe Moxifloxacin-Impregnated Contact Lenses for Treatment of Keratitis in Rabbit Eyes(Wiley, 2025) Erdogan, Hakika; Gungor, Buket; Suner, Selin S.; Silan, Coskun; Saraydin, Serpil U.; Saraydin, Dursun; Ayyala, Ramesh S.Moxifloxacin (MOX) was loaded into commercial contact lenses (CLs) via supercritical carbon dioxide (ScCO2) to attain MOX-impregnated CL for keratitis treatment. This study aimed to investigate Pseudomonas keratitis treatment with MOX-impregnated CL compared to the traditional eyedrop administration. MOX impregnation was accomplished employing optimum parameters of 2.5 h drug exposure time, 25 MPa pressure, and 313 K for ScCO2 conditions using ethanol co-solvent rendering sustainable delivery, up to 7 days at effective dosage formulation. The MOX-impregnated CL was found to be safe with no significant toxicity on fibroblast cells after 5 days of contact time. Bacterial viability in vivo keratitis treatment in rabbit eyes was significantly decreased to 10(2) from 10(9) CFU/cornea for MOX-impregnated CL treatment, almost similar to exhaustive conventional 0.5% MOX eye drop treatments. The MOX-impregnated CL treatment revealed no conjunctival hyperemia, edema, or secretion for all eyes in the relevant group, and transparent cornea with no keratitis focus was obtained for two of the eyes (n = 6). The normal histological structure was seen with MOX-impregnated CL treatment on healthy eyes. Moreover, polymorphonuclear cell infiltration observed in keratitis eyes without any treatment was significantly decreased to a few polymorphonuclear cells in the groups treated with MOX eyedrops and MOX-impregnated CL.Öğe Poly(acrylamide-sepiolite) composite hydrogels: Preparation, swelling and dye adsorption properties(SPRINGER, 2006) Ekici, Sema; Isikver, Yasemin; Saraydin, DursunPolymer-clay hydrogel composite was prepared on the basis of polyacrylamide (PAAm) gel containing the clay mineral sepiolite. The properties of swelling and dye adsorption of poly(acrylamide-sepiolite) (AAm/Sep) composite hydrogel were investigated. The parameters of swelling and diffusion in water and dye solutions were calculated for the AAm and AAm/Sep hydrogels. It was found that the equilibrium swelling degree of obtained composite higher than that of AAm gel. Spectroscopic analysis of composite and composite-dye systems was done with FT-IR method. Adsorption of monovalent cationic dyes such as Basic Blue 12 (BB-12) Basic Blue 9 (BB-9), and Basic Violet 1 (BV-1), was studied on the composite. In the adsorption experiments, S (Sigmoidal) type for composite gel adsorption isotherms in the Giles classification system was found. Adsorption studies indicated that the amounts of adsorbed dyes on the AAm/Sep composite hydrogel were increased with following order; BB-12 > BB-9 > BV-1. The composite hydrogel may be considered as good candidate for environmental application to retain more water and dyes.Öğe Poly(acrylamide/maleic acid)-sepiolite composite hydrogels for immobilization of invertase(SPRINGER, 2010) Oztop, H. Nursevin; Hepokur, Ceylan; Saraydin, DursunPoly(acrylamide/maleic acid) and sepiolite (PAMS) composite hydrogel was prepared and used for the immobilization of invertase. In FTIR analysis, the characteristic bands of composite such as -OH, -COOH, Si-OH show the evidence of sepiolite and maleic acid. In TGA analysis, water loss, decomposition of amide side groups and breakdown of main chain regions of the composite were found. The parameters of equilibrium swelling, initial swelling rate, diffusional exponent, and diffusion coefficient were calculated and evaluated from swelling experiments in distilled water. Invertase was immobilized onto PAMS by adsorption and poly(acrylamide/maleic acid)-sepiolite-invertase (PAMSI) was prepared. Optimum pH, optimum temperature values for free invertase and PAMSI were found. It was found that K (m) values of free invertase and PAMSI were 11.3 and 34.1 mM, respectively. V (max) value was found that 2.0 mu mol min(-1) for free invertase and 13.9 mu mol min(-1) for PAMSI, respectively. PAMSI showed excellent temperature, operational and storage stability.
