DSpace Arşivi :: by Yazar "Salgin, Sema" değerine göre listeleniyor

Yazar "Salgin, Sema" seçeneğine göre listele

Listeleniyor 1 - 20 / 22

Adsorption of Bisphenol A onto β-Cyclodextrin-Based Nanosponges and Innovative Supercritical Green Regeneration of the Sustainable Adsorbent
(MDPI, 2025) Salgin, Ugur; Alomari, Ismail; Soyer, Nagihan; Salgin, Sema
Bisphenol A is a widely recognized endocrine disruptor that persists in ecosystems, harms aquatic organisms, and contributes to ecological degradation, raising global environmental concerns. Numerous studies have explored beta-cyclodextrin-based adsorbents for Bisphenol A removal; however, their regeneration remains a major challenge, often relying on energy-intensive processes and excessive use of organic solvents. In this study, Bisphenol A was selected as a model pollutant, and its adsorption onto beta-cyclodextrin nanosponges was investigated. After adsorption, Bisphenol A was efficiently recovered from the saturated beta-cyclodextrin nanosponges using an innovative and sustainable supercritical CO2-based green process, which simultaneously regenerated the adsorbent. The adsorption process achieved an efficiency of 95.51 +/- 0.82% under optimized conditions (C-0 = 150 mg/L, m(beta-CDNS) = 0.15 g, T = 25 degrees C, and N = 200 rpm), with a maximum adsorption capacity of 47.75 +/- 0.28 mg/g. The regeneration process achieved over 99% efficiency at 60 degrees C and 300 bar, with 10% (v/v) ethanol as a co-solvent, nearly fully restoring the adsorbent's performance. Unlike conventional regeneration techniques, this green approach eliminates the need for environmentally harmful organic solvents while preserving the adsorbent's structural integrity, making it a highly efficient and sustainable alternative. This study is the first to demonstrate the effective application of supercritical CO2-based regeneration for beta-cyclodextrin nanosponges in Bisphenol A removal, providing a scalable and environmentally sustainable solution for wastewater treatment. Furthermore, characterization analyses confirmed that the adsorbent retained its chemical and morphological stability after adsorption and regeneration.
Bioconjugation of Magnetic Iron Oxide Nanoparticles and Cross-Linked Enzyme Aggregates: Characterization and Comparison of CLEAs and Magnetic CLEAs
(BENTHAM SCIENCE PUBL LTD, 2017) Salgin, Sema; Salgin, Ugur
Background: The separation of enzymes from the bio-product medium constitutes a significant part of total process cost. Therefore, it is of crucial importance that the separation processes for enzymes be specially developed. In this study, the advantages of cross-linked enzyme aggregates (CLEAs) and magnetic iron oxide nanoparticles (MIONPs) have been combined in magnetic CLEAs matrix. Methods: MIONPs were produced by co-precipitation methods. The synthesized MIONPs and CLEAs were characterized by scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), dynamic light scattering (DLS), phase analysis light scattering (PALS), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA) analyses. Results: Optimal pH and temperature values of magnetic and non-magnetic CLEAs have been determined to be pH= 7.5 and T= 45 degrees C. It has been observed that there are differences in apparent KM and V-max values of magnetic and non-magnetic biocatalysts. Moreover, the high activity of nonmagnetic CLEAs is a result of low alpha-helix and beta-sheet contents. Compared with non-magnetic CLEAs, magnetic CLEAs showed high storage stability and good reusability. Due to the different the protein content, the weight loss of the non-magnetic and magnetic CLEAs determined by TGA was about 65% and 53%, respectively. From DSC analysis, the denaturation temperatures of nonmagnetic and magnetic CLEAs were 97 +/- 0.8 degrees C and 108 +/- 0.8 degrees C, respectively. Conclusion: The present work provided important information on production, comparison and characterization of non-magnetic and magnetic CLEAs from Candida rugosa lipase (CRL) enzyme. The magnetic CLEAs had significant enhancement on the storage stability, thermal stability, reusability comparing with that of non-magnetic CLEAs. These improved properties of magnetic CLEAs could be an attractive feature towards more stable CLEAs preparation. The high cost of complex separation processes could be eliminated with magnetic CLEAs.
Crossflow ultraflitration of binary biomolecule mixture: Analysis of permeate flux, cake resistance and sieving coefficient
(WILEY-V C H VERLAG GMBH, 2007) Salgin, Ugur; Salgin, Sema
The aim of this paper is to demonstrate the effects of hydrodynamic conditions on the permeate flux, cake resistance and sieving coefficient in a crossflow ultrafiltration process separating biomolecules of different molecular weights. A binary mixture of L-phenylalanine (L-phe) and lipase was ultrafiltered through a hydrophobic polyether sulphone (PES) membrane with 10 kDa molecular weight cut-off. The changes in permeate flux, cake layer resistance and observed sieving coefficient with different transmembrane pressures (TMP) and crossflow velocities were evaluated. The effect of TMP was examined at two different velocities (0.114 m s(-1) and 0.176 in s(-1)) and the effect of velocity was examined at two different TMP (20 kPa and 115 kPa) for the experimental system designed. In the initial stage of the crossflow filtration, it was determined that the TMP was more effective than the velocity. The cake layer resistance increased with increasing TMP and it decreased with increasing velocity for the high TMP value of 115 kPa. A maximum of the observed sieving coefficient was achieved with increasing velocity. An increase in TMP at low inlet velocity (0.114 in s(-1)) affected the observed sieving coefficient positively.
Determination of correct zeta potential of polyether sulfone membranes using CLC and AGC: ionic environment effect
(TAYLOR & FRANCIS INC, 2016) Salgin, Sema; Salgin, Ugur; Tuzlali, Nagihan
In this study, the correct and apparent zeta potential of polyether sulfone (PES) ultrafiltration membranes at different ionic environments were determined using streaming potential measurements. The apparent zeta potential was found by calculation with classic Helmholtz-Smoluchowski (HS) and Fairbrother-Mastin (FM) equations of results obtained from clamping cell (CLC) and adjustable gap cell (AGC). Correct zeta potential was determined by calculation with a modified HS equation of obtained results from AGC. Obtained apparent zeta potential results from CLC and AGC differ from each other, and the reproducibilityof results was found to be higher for measurements of AGC. Except for low pH values, apparent zeta potential that was obtained from classic HS equation with AGC could be accepted as correct zeta potential. In CLC measurements, underestimated or overestimated zeta potential values were determined in comparison with the correct zeta potential. The effect of membrane surface conductance on zeta potential decreased with increasing KCl concentration. In CLC, the deviation was observed from electrical double layer theory when KCl concentration was 0.1M, therefore streaming potential measurements did not produce correct results at higher salt concentration. 0.001M KCl concentration was the value at which surface conductance became crucial.
Effect of main process parameters on extraction of pine kernel lipid using supercritical green solvents: Solubility models and lipid profiles
(ELSEVIER SCIENCE BV, 2013) Salgin, Ugur; Salgin, Sema
Supercritical fluid extraction of pine kernel lipids from Pinus pinea L using green solvents (only CO2 or mixed with ethanol) was performed in a laboratory scale extraction system. For the first time in this study the effect of main operating parameters [i.e. pressure (20-50 MPa), temperature (40-60 degrees C), CO2 flow rate (0.061-0.259 kg h(-1)), entrainer concentration (2.5 and 5 vol.%) and average particle size (362.5 and 725 mu m)] on extraction yield, initial extraction rate and the solved contents of pine kernel lipid in CO2 or its solubility was investigated systematically. Experimental results showed that extraction yields (from 0.477 to 0.488 g PKLg(-1) dry PK) obtained from supercritical CO2 extraction over 30 MPa of operating pressure was better than extraction yield (0.472g PKLg(-1) dry PK) obtained from organic solvent extraction. It should be noted that the extraction yield obtained using 5 vol.% of ethanol reached to 0.487 g PKLg(-1) dry PK in 90 min under a suitable operating condition such as 30 MPa, 40 degrees C and 0.194 kg h(-1) of green solvent flow rate. The crossover effect of pine kernel lipid was determined approximately at 23 MPa of operating pressure. The experimental solubility data, determined by the dynamic method, of pine kernel oil in supercritical CO2 were correlated by some empirical models such as Chrastil, del Valle-Aguilera, Adachi-Lu, and Sparks models. Adachi-Lu and Sparks models made a lower error in the prediction of solubility. Lipids extracted by supercritical green solvents extraction contain more unsaturated fatty acids than those extracted by Soxhlet with in the n-hexane extracts. (C) 2012 Elsevier B.V. All rights reserved.
Effect of Reaction Parameters on the Synthesis of Cyclodextrin-Based Nanostructured Polymers for Drug Delivery
(MDPI, 2025) Salgin, Sema; Eke, Hasan Huseyin; Soyer, Nagihan; Salgin, Ugur
In this study, cyclodextrin-based nanostructures (CDNSs) were synthesized through the cross-linking of cyclodextrin (CD) with epichlorohydrin (ECH) as a cross-linker. Two types of CDNSs, alpha-CDNS and beta-CDNS, were prepared to systematically investigate the influence of reaction parameters-such as the solubilization time of alpha-CD and beta-CD, the molar ratio of ECH to CD, and NaOH concentration-on the physicochemical properties of the final product. Naproxen (NAP), a poorly water-soluble drug, was selected as a model compound to assess the drug-loading capacity of the synthesized CDNSs. The effect of each reaction parameter on NAP integration into the CDNSs was examined at varying weight ratios. The optimal reaction conditions were determined to be a solubilization time of 6 h, an ECH/CD molar ratio of 8/1, and an NaOH concentration of 33%. Under these conditions, the NAP loading efficiency of alpha-CDNSs was calculated as 67.12%. Comparative analysis revealed that alpha-CDNSs outperformed beta-CDNSs in terms of drug-loading capacity. Additionally, the synthesized CDNSs and NAP-loaded CDNSs were characterized using FTIR, DSC, XRD, SEM, and Zetasizer analyses, while the NAP concentration was determined by HPLC.
Effects of additives on the activity and enantioselectivity of Candida rugosa lipase a in a biphasic medium
(WILEY-V C H VERLAG GMBH, 2007) Salgin, Sema; Takac, Serpil
The effects of Li+, Na+, K+, Mg2+ and Zn2+ ions on the activity and enantioselectivity of Candida rugosa lipase (CRL) were investigated in a biphasic medium composed of phosphate buffer solution (containing a metal ion within a 50-500 mM concentration range) and isooctane. The hydrolytic activities of CRL towards p-nitrophenyl acetate were measured after incubation of the enzyme in the presence of metal ions for 24 h, and they were compared to that obtained after incubation in the absence of any metal ion. The CRL activity was stimulated by the chloride salts of Li+, K+ and Mg2+ for all concentrations considered and the highest enhancement was achieved by Li+ with a 1.24-1.75 fold increase observed. The effects of metal ions on the enantioselectivity of CRL were investigated by performing the hydrolysis of racemic Naproxen methyl ester in the same biphasic medium containing Li+, Na+, K+, Mg2+ and Zn2+ ions. The addition of metal ions increased the hydrolysis rate by ca. 1.31-1.45 fold relative to the control, whereas the enantiomeric excess of product increased slightly in the presence of the metal ions. The effect of Triton X-100 on the activity and enantioselectivity of the CRL was also investigated by employing 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 mM concentrations of it in phosphate buffer solution of the biphasic medium. High concentrations of Triton X-100 stimulated the enzyme activity up to 1.66 fold after 24 h incubation. Triton X-100 increased the hydrolysis rate almost independently of the concentration.
Effects of ionic environment on the interfacial interactions between alpha-amylase and polyether sulphone membranes
(WILEY-BLACKWELL, 2011) Salgin, Sema
This work reports a systematic study on the effects of ionic environment on the adsorption of alpha-amylase on 30 kDa polyether sulphone (PES) membranes on the basis of interfacial interaction of PES membrane and alpha-amylase enzyme in solution. Static adsorption of alpha-amylase was investigated at the solution pH values of pH = 4.5, 5.6 and 7.0; and for the ionic strengths of 0.001, 0.01 and 0.1 M KCl. The maximum adsorption occurred at the pH value below the isoelectric point (IEP) of the enzyme, whereas the minimum adsorption occurred at the IEP (pH = 5.6) of amylase. With increasing ionic strength, the adsorbed enzyme on the membrane decreased. The Freundlich and Langmuir adsorption models were used for the mathematical description of the adsorption equilibrium and isotherm constants were evaluated depending on ionic environment. To determine the steps affecting the adsorption mechanism, the experimental data were evaluated using pseudo-first-order and pseudo-second-order kinetic models. The experimental data fitted well the pseudo-first-order kinetics. To detect the structural changes which occurred, membrane surfaces were analyzed by FTIR-ATR spectroscopy. The effects of ionic environment on amylase activity were also investigated. Copyright (C) 2010 John Wiley & Sons, Ltd.
Effects of ionic environments on bovine serum albumin fouling in a cross-flow ultrafiltration system
(WILEY-V C H VERLAG GMBH, 2007) Salgin, Sema
The influence of electrostatic interactions on membrane fouling during the separation of bovine serum albumin (BSA) from solution was studied in a cross-flow ultratiltration system. Experiments were carried out at different pH values between 3.78 and 7.46; and for different ionic strengths between 0.001 M and 0.1 M. The changes in permeate flux, cake layer resistance, zeta potentials of BSA and polyether sulfone (PES) membranes, and electrostatic interaction energies, were evaluated. At all of the ionic conditions studied, PES membranes are negatively charged. However, BSA molecules are either negatively or positively charged depending on the ionic environment. Whereas the cake layer resistance decreased with increasing pH and ionic strength, the permeate fluxes increased. The calculated electrostatic energy was a minimum at the isoelectric point (IEP) of BSA. However, at this point, the cake resistances corresponding to fouling at each ionic strength, were not minimized. Below the IEP of BSA, the electrostatic forces were attractive, while above the IEP, repulsive electrostatic forces were dominant.
Enantiomeric separation of antidepressant drug fluoxetine based on chiral membranes
(DESALINATION PUBL, 2018) Salgin, Sema; Salgin, Ugur; Tuzlali, Nagihan
In this study, the enantiomeric separation of antidepressant drug fluoxetine (FLX) was carried out using chiral selector-immobilized polyethersulfone (PES) membranes. For this purpose, the chiral selectors BSA, Candida rugosa lipase (CRL) and alpha-cyclodextrine (alpha-CD) were adsorbed on PES membranes by the static adsorption at different pH values. Chemical and electrokinetic characterizations of modified membranes were done by Fourier transforms infrared (FTIR) spectroscopy and by an electrokinetic analyzer (EKA), respectively. FTIR and EKA analysis were particularly employed in order to evaluate the immobilization efficiency. Racemic FLX was ultrafiltrated with the chiral selective membranes using the stirred ultra filtration cell. The effectiveness of chiral separation was characterized in terms of the values of enantiomeric excess (ee%) in permeate. During the ultra filtration, the samples taken from permeate were analyzed with liquid chromatography system using Chiral-pak AD-H column for the determination of R-FLX and S-FLX enantiomers. The ee(s) values of BSA and CRL in the permeate were approximately equal.
Enantiomeric separation of fluoxetine in ultrafiltration through chiral selector-immobilized polyethersulfone membranes
(ELSEVIER SCIENCE BV, 2012) Soyer, Nagihan; Salgin, Sema; Salgin, Ugur
…
The enantioselective hydrolysis of racemic naproxen methyl ester in supercritical CO2 using Candida rugosa lipase
(ELSEVIER SCIENCE BV, 2007) Salgin, Ugur; Salgin, Sema; Takac, Serpil
The enantioselective hydrolysis of racemic naproxen methyl ester by Candida rugosa lipase (CRL) was studied in aqueous buffer solution/isooctane reaction system in the presence of supercritical CO2. The effects pressure (75-160 bar), temperature (32-42 degrees C ) and reaction time (0.5-12 h) on the enantiomeric excesses of the product (ee(p)) and the substrate (ee(s)), enantiomeric ratio (E), conversion (x) and enzyme activity were investigated in a batch reactor system. The highest enantiomeric ratio achieved at 120 bar of pressure, 37 C of temperature and 2 h of reaction time was E= 193 with x=41.3%, ee(p)=97.9% and ee(s)=68.8%. CRL remained active at least for 12h at 37 degrees C and 120 bar in supercritical CO2 medium. Furthermore. enantiomeric ratio increased with increasing reaction time and reached the value of E=236 with ee(p) =98.2%, ee(s) =70.0% and x=41.6% after 12 h of hydrolysis. (C) 2007 Elsevier B.V. All rights reserved.
Kinetic resolution of racemic naproxen methyl ester by magnetic and non-magnetic cross-linked lipase aggregates
(Taylor & Francis Inc, 2020) Salgin, Sema; Cakal, Mustafa; Salgin, Ugur
In this study, the non-magnetic and the magnetic cross-linked enzyme aggregates (CLEAs) from Candida rugosa lipase were synthesized to catalyze the kinetic resolution reaction of naproxen methyl ester (NME). Magnetic iron oxide nanoparticles (MIONPs) were produced through co-precipitation method and their surfaces were modified by silanization reaction. The MIONPs were used as a platform to synthesize the magnetic CLEAs (M-CLEAs). The biocatalysts and MIONPs synthesized were characterized by FTIR spectroscopy and SEM analysis. The kinetic resolution of racemic NME was studied in aqueous buffer solution/isooctane biphasic system to compare the performance of M-CLEAs and CLEAs. The effects of reaction parameters such as temperature, pH, stirring rate on the enantiomeric excess of the substrate (ee(s)%) were investigated in a batch reactor system. The activity recovery of CRL enzyme in CLEAs was higher than M-CLEAs. Compared with M-CLEAs, CLEAs biocatalysts had previously reached ee(s)% values. Although both biocatalysts showed similar cavity structure from SEM analysis, the lower performance of M-CLEAs may be due to the different microenvironments of M-CLEAs from CLEAs. However, the reusability performance of M-CLEAs was higher than that of CLEAs. The optimal reaction conditions for M-CLEAs and CLEAs were found to be 37 degrees C, pH 7.5, and 300 rpm.
A new application of supercritical CO2 technology for cross linked enzyme aggregates
(ELSEVIER SCIENCE BV, 2012) Dincyurek, Derya; Aptis, Hasan; Salgin, Sema; Salgin, Ugur
…
Oil recovery in rosehip seeds from food plant waste products using supercritical CO2 extraction
(ELSEVIER SCIENCE BV, 2016) Salgin, Ugur; Salgin, Sema; Ekici, Derya Dincyurek; Uludag, Gamze
Valuable oils in rosehip seeds produced as the solid waste during the process of marmalade production using seed-containing fruits were recovered by supercritical CO2 extraction method. The influence of the particle size (125 <= Dp > 1000 mu m), volumetric flow rate of supercritical solvent (0.75-3.5 mL/min), pressure (20-40 MPa), temperature (40-60 degrees C) and entrainer concentration (2.5-7.5%vol. ethanol) on the extraction yield in the recovery process was examined. The highest extraction yield determined as 16.5 g oil/100 g dry solid was reached in approximately 150 min by using supercritical CO2 extraction (30 MPa, 40 degrees C, 0.75 mL/min, 355 < Dp < 500 mu m) and in the case where 5%vol. ethanol is used as entrainer, it was reached in about 90 min. In similar oil profiles obtained through Soxhlet and supercritical fluid extractions, the ratio of unsaturated fatty acids to saturated fatty acids is about 17. Significant changes were determined in morphological structures of waste seeds compared to unprocessed seeds in marmalade production, by using scanning electron microscope. Apparent solubility values of rosehip oil in supercritical CO2 did exhibit a significant consistency with Chrastil, del Valle-Aguilera, Adachi-Lu and Sparks solubility models. (C) 2016 Elsevier B.V. All rights reserved.
Streaming Potential Measurements of Polyethersulfone Ultrafiltration Membranes to Determine Salt Effects on Membrane Zeta Potential
(ESG, 2013) Salgin, Sema; Salgin, Ugur; Soyer, Nagihan
A systematic study on the zeta potential of polyethersulfone membranes determined by streaming potential measurements was made to examine various salt effects. Chloride salts; KCl, NaCl, CaCl2 and MgCl2 and potassium salts; KCl, KNO3, KClO3, K2CO3, K2SO4 and K2Cr2O7 were used to investigate the effects of cations and anions on the zeta potential of membranes, respectively. The zeta potential was obtained in 0.001 M salt solutions at the range of pH=4.0-8.0. The effect of ionic strength on membrane zeta potential was also investigated in the solution of KC1 and Na2HPO4 with 0.001 M-0.1 M salt concentrations. At high pH values, anion adsorption on membrane surface had a more potent effect on zeta potential, while at low pH values, cation adsorption to membrane surface also possessed more potent effect on zeta potential. In general, zeta potential decreased with increasing ionic strength due to the compression of electrical double layer. However, preferential adsorption of ions on the membrane surface is another important parameter affecting zeta potential beside the ionic strength. The influence of ionic strength on the membrane zeta potential can be observed by performing FTIR-ATR analysis.
Supercritical fluid extraction of walnut kernel oil
(WILEY-V C H VERLAG GMBH, 2006) Salgin, Sema; Salgin, Ugur
The objective of this study was to investigate the effects of the main process parameters on supercritical fluid extraction of walnut (Juglans regia L.) kernel oil. The recovery of walnut kernel oil was performed in a green and high-tech separation process. CO2 and CO2 + ethanol mixtures were used as the supercritical solvent. The extraction was carried out at operating pressures of 30, 40 and 50 MPa, operating temperatures of 313, 323 and 333 K, mean particle sizes of 1.78 x 10(-4), 3.03 x 10(-4), 4.78 x 10(-4), 7.00 x 10(-4) and 9.00 x 10(-4) m, supercritical CO2 (SC CO2) flow rates of 1.67 x 10(-8), 3.33 x 10(-8), 6.67 x 10(-8) and 13.33 x 10(-1) m(3)/s and entrainer (ethanol) concentrations of 2, 4, 8 and 12 vol-%. Maximum extraction yield and oil solubility in SC CO2 obtained at 50 MPa, 333 K, 9.00 x 10(-4) m, 3.33 x 10(-4) m(3)/h were 0.65 kg oil/kg of dry sample and 37.16 g oil/kg CO2, respectively. The results obtained in this study showed that the crossover pressure effect of walnut kernel oil was at 30 MPa. At 30 MPa and 313 K, the obtained extraction yields above 4 vol-% ethanol reached the organic solvent extraction yield of 68.5 kg oil/kg dry sample. Extraction time was decreased significantly because of the higher solubility of walnut kernel oil in SC CO2 + ethanol mixtures.
Synthesis and characterization of ?-cyclodextrin polymers and its performance as a drug carrier
(Taylor & Francis Inc, 2024) Salgin, Sema; Cetintas, Halil Ibrahim; Salgin, Ugur
The aim of this study was to determine the optimal reaction conditions for the synthesis of hyperbranched cyclodextrin polymer (CDP) and to investigate their performance as drug carriers. In this study, beta-Cyclodextrin (beta-CD) was used as the basis for CDP nanocarriers, which were synthesized by reacting beta-CD with pyromellitic dianhydride (PMDA) as a crosslinking agent. The effects of beta-CD/PMDA molar ratio and reaction time were investigated to optimize the synthesis of CDP. The optimal reaction conditions were determined to be a reaction time of 2 h and a molar ratio of 1/12 beta-CD/PMDA. Ketoprofen (KP) was used as a model drug to evaluate the loading capacity of CDP. The effects of KP/CDP (w/w) loading ratio, temperature, and stirring speed on the formation of the KP/CDP inclusion complex were investigated. The optimum conditions for loading KP into CDP were found to be 1/4 KP/CDP ratio, 4 h, 35 degrees C, and 300 rpm with a loading efficiency of 39.57%. Characterization of the CDP was performed using Zetasizer, FTIR, DSC, SEM and XRD analysis.
Synthesis and Characterization of beta-Cyclodextrin Nanosponge and Its Application for the Removal of p-Nitrophenol from Water
(WILEY, 2017) Salgin, Sema; Salgin, Ugur; Vatansever, Ozgun
beta-Cyclodextrin (beta-CD)-based nanosponges (NSs) were synthesized by reacting beta-CD with hexamethylenediisocyanate (HMDI) as the cross-linking agent. The effects of the reaction parameters, such as the beta-CD/HMDI molar ratio, reaction temperature, and type of cross-linker, on the NS synthesis were systematically examined. The removal of p-nitrophenol (p-NP) from water by NSs was determined through adsorption experiments. The adsorption efficiency of the NSs synthesized at different temperatures did not change significantly, but the adsorption efficiency of the NSs was influenced by the HDMI concentration and cross-linker type. The characteristic Fourier transform infrared (FTIR) bands showed that p-NP was adsorbed parallel to the surface of the NSs. The Langmuir model had the highest correlation coefficient for the adsorption of p-NP onto the NSs. The maximum adsorption capacity (Q degrees) and adsorption energy (b) for p-NP were estimated to be 1.0 mg g(-1) and 1.837 Lmg (-1), respectively. The NSs synthesized under the optimum conditions were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and laser diffraction particle size (LDPS) analysis. The combination of the results from SEM, TEM, and LDPS analysis indicated that the synthesized NSs had a porous, sponge-like, and rigid structure. The results of XRD and TGA also revealed the formation of beta-CD-NSs.
Synthesis, optimization, and characterization of β-cyclodextrin-based biological metal-organic frameworks as drug carriers
(Springer Int Publ Ag, 2025) Cetintas, Halil Ibrahim; Salgin, Sema; Salgin, Ugur
In this study, beta-cyclodextrin (beta-CD)-based metal-organic frameworks (MOFs) were synthesized using the vapor diffusion method, a cost-effective and straightforward approach, to evaluate their potential as drug delivery systems. Ketoprofen (KP), a poorly water-soluble nonsteroidal anti-inflammatory drug (NSAID), was used as a model drug. The effects of reaction time, temperature, ligand-to-metal salt molar ratio and cetrimonium bromide (CTAB) surfactant addition on the properties of beta-CD-Bio-MOFs were systematically investigated. Optimal synthesis conditions-1 day, 30 degrees C, and a 1:4 beta-CD:KOH molar ratio-produced quadrilateral crystals averaging 10-20 mu m in size. Using KCl as the metal source yielded uniform crystals (10-40 mu m), whereas NaOH and FeCl3 did not result in consistent structures. Adding CTAB as a surfactant further reduced crystal sizes to 5-20 mu m. Also, KP loading experiments were conducted to optimize parameters such as temperature, agitation speed, loading time, solvent medium, and mass ratio for achieving maximum loading efficiency. The optimal conditions were determined to be 25 degrees C, 200 rpm, and 3 h in ethanol. Under these conditions, loading efficiencies of 13.4%, 9.6%, and 15.8% were achieved for beta-CD-Bio-MOF, KCl-beta-CD-Bio-MOF, and CTAB-beta-CD-Bio-MOF samples, respectively, with corresponding surface areas of 11.8, 9.7, and 18.4 m2 g-1. In comparison, pure beta-CD, with a specific surface area below 5 m2 g(-)1, exhibited a lower loading efficiency of 4.1%.

Yazar "Salgin, Sema" seçeneğine göre listele

Sayfa Başına Sonuç

Sıralama seçenekleri