94 research outputs found
Halloysite-carboxymethyl cellulose cryogel composite from natural sources
No full textIn this work, novel superporous composite cryogel using natural source such as carboxymethyl cellulose (CMC) and halloysite nanotubes (Hal nanotubes) was prepared. The composite was prepared via cryogelation method including the Hal nanotubes within polymeric matrices before cryogelation. A series of the Hal nanotubes/carboxymethyl cellulose composite were prepared by varying the used amounts of crosslinker, and Hal nano tubes amounts. Additionally, Hal nanotubes were modified with different modifying agent such as (3-aminopropyl)triethoxysilane (APTES), (3-chloro-2-hydroxypropyl)trimethylammonium chloride (CHPTACI), polyethylenimine (PEI), epichlorohydrin (ECH), diethylenetriamine (DETA), taurine (TA), and tris(2-aminoethyl)amine (TAEA), these modified Hal nanotubes were used in CMC cryogel composite preparation. Characterization of the synthesized materials was performed by Scanning and Transmission Electron Microscopy (SEM and TEM), Zeta Potential (ZP) measurement, Thermogravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR) spectroscopic measurement and Surface area and Porosity Analyzer. (C) 2017 Elsevier B.V. All rights reserved.Turkish Academy of Science (TUBA)Turkish Academy of SciencesN. Sahiner is grateful to the Turkish Academy of Science (TUBA-2008) for financial support under the 2008-TUBA GEBIB program
Hydrolytic nondegradable bioactive rosmarinic acid particles
No full textRosmarinic acid (RS) is as the nonflavonoid polyphenols in the phenolic acid subgroup was cross-linked with sodium trimetaphosphate (STMP) to obtain (p[RS-co-STMP]) particles with the size distribution of 2.992 ± 659 nm. The zeta potential values of p(RS-co-STMP) particles were measured between pH 2–10, and the isoelectric point was determined as pH 2.66. Fe(II) chelating capability test was done for RS and p(RS-co-STMP). At 800 μmol/ml concentrations, p(RS-co-STMP) particles chelated 95.06 ± 5.18% Fe(II), while RS molecule did not chelate Fe(II), whereas STMP chelated only 41.8 ± 5.9% Fe(II). The effects of RS and p(RS-co-STMP) particles on α-glucosidase enzyme activity were investigated and were found to inhibit the α-glucosidase enzyme by 55.7% and 89.6%, respectively. Furthermore, p(RS-co-STMP) particles were modified with polyethyleneimine as m-p(RS-co-STMP) to improve antimicrobial properties and found effective against both Escherichia coli and Staphylococcus aureus bacteria. The interaction of fibrinogen with RS, p(RS-co-STMP) and m-p(RS-co-STMP) were studied via the change in intensity of corresponding fluorescence spectra. It was found that p(RS-co-STMP) particles interacted lesser with fibrinogen than RS and changed the fluorescence property of fibrinogen protein slightly. On the other hand, m-p(RS-co-STMP) particles did not change the fluorescence intensity of fibrinogen suggesting no influence on the blood clotting
Enhanced Bioactive Properties of Halloysite Nanotubes via Polydopamine Coating
No full textHalloysite nanotubes (HNT) were coated five times with dopamine (DOPA) in a tris buffer medium at pH 8.5 to acquire polydopamine-coated HNTs (PDOPA@HNT), e.g., PDOPA1@HNT, PDOPA3@HNT, and PDOPA5@HNT. Upon coating HNT with PDOPA, the surface area, pore volume, and pore size were decreased depending on the number of coatings. While the surface area of HNT was 57.9 m2/g, by increasing the number of coatings from 1 to 5, it was measured as 55.9, 53.4, 53.3, 47.4, and 46.4 m2/g, respectively. The isoelectric point (IEP) for HNTs was determined as 4.68, whereas these values are estimated as 2.31 for PDOPA1@HNTs, 3.49 for PDOPA3@HNT, and 3.55 for PDOPA5@HNT. Three different antioxidant studies were conducted for HNT and PDOPA@HNT, and the total phenol (TPC) value of HNT was found to be 150.5 ± 45.9 µmol gallic acid (GA) equivalent. The TPC values for PDOPA1@HNT, PDOPA3@HNT and PDOPA5@HNT coatings were found to be 405.5 ± 25.0, 750.0 ± 69.9, and 1348.3 ± 371.7 µmol GA equivalents, respectively. The Fe(II) chelation capacity of HNT was found to be 20.5% ± 1.2%, while the PDOPA1@HNT, PDOPA3@HNT and PDOPA5@HNT values were found to be 49.9 ± 6.5, 36.6 ± 12.7 and 25.4 ± 1.2%, respectively. HNT and PDOPA@HNTs inhibited the α-glucosidase (AG) enzyme to greater extents than acetylcholinesterase (AChE). As a result, the DOPA modification of HNTs was rendered to provide additional characteristics, e.g., antioxidant properties and higher AChE and AG enzymes inhibition capabilities. Therefore, PDOPA@HNTs have great potential as biomaterials
Application of superporous magnetic cationic cryogels for persistent chromate (toxic chromate and dichromate) uptake from aqueous environments
No full textPoly((3-Acrylamidopropyl) trimethylammonium chloride) (p(APTMACl)) cryogels were prepared with cryopolymerization technique and employed for the removal of toxic chromate and dichromate anions from aqueous media. The maximum adsorption capacities of 94 mg/g and 135 mg/g for chromate and dichromate anions, respectively, were determined with the application of the Langmuir isotherm. These values are very close to the experimental values of about 77 and 128 mg/g from 100 mL, 100 ppm chromate, and dichromate solutions using 0.03 g cryogel. The removal efficiency of chromate and dichromate anions were increased with the increase in the amount of cryogel and the removal percentage of chromate and dichromate toxic anions were estimated as 99.21 and 93.61%, respectively, for 0.15 g of p(APTMACl) cryogels used in 100 mL, 100 ppm chromate, and dichromate solutions. Furthermore, magnetic p(APTMACl) cryogels were also prepared and used in the removal of chromate and dichromate, and the maximum adsorption capacities were 30 mg/g and 40 mg/g, respectively. Additionally, the adsorption of these anions were investigated from different media such as drinking water, tap water, seawater, and creek water; and the maximum adsorption amounts in drinking water were 65.5 +/- 15, and 125.5 +/- 11 mg/g for chromate and dichromate anions, respectively. The reusability of p(APTMACl) cryogels for the removal of chromate and dichromate anions was also investigated, and it was found that the adsorption capacity for chromate anions decreased to 71.23 +/- 4.3 from 97.37 +/- 4.5 mg/g, whereas the adsorption capacity of dichromate anions only decreased to 123.69 +/- 3.5 mg/g from 129.9 +/- 7 mg/g at the end of five adsorption-desorption cycles. (C) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43438.Canakkale Onsekiz Mart University Scientific Research CommissionCanakkale Onsekiz Mart University [COMU-BAP:2014-284]The authors are grateful for the financial support of Canakkale Onsekiz Mart University Scientific Research Commission (COMU-BAP:2014-284)
Synthesis and characterization of poly(Naringin) particles as new biomaterials
No full text255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water -- MAR 18-22, 2018 -- New Orleans, L
Rosmarinic acid particles with versatile biomedical functions
No full text255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water -- MAR 18-22, 2018 -- New Orleans, L
Preface of Symposium “Modern and Classical Optimization Techniques in Multi Disciplinary Studies”
No full textSuperporous hyaluronic acid cryogel composites embedding synthetic polyethyleneimine microgels and Halloysite Nanotubes as natural clay
No full text3rd International Conference on Bio-Based Polymers and Composites (BiPoCo) -- AUG 28-SEP 01, 2016 -- Szeged, HUNGARYIn this study, the preparation of hyaluronic acid (HA) cryogels were carried out in the presence of polyethyleneimine (PEI) microgels, and Halloysite Nanotubes (HNTs) clays separately resulted in the corresponding cryogel composites under cryogenic condition ( < 0 degrees C). The synthesized HA/PEI cryogel microgel composites, and HA/HNTs cryogel composites were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and by the swelling studies to compare % pore volume and porosity values of the composite materials. The swelling properties and moisture content of HA cryogel, HA/PEI and HA/HNTs cryogel composites were determined at wound healing pH conditions such as pH 5.4, 7.4, and 9 at 37.5 degrees C. The highest swelling capacity was reached at pH 9 with 4854 +/- 50% swelling (S%) within few seconds. The blood compatibility of the HA cryogel and its' PEI microgel and HNT embedding composite were found to be hemocompatible with maximum of 2.4% hemolysis ratio, and demonstrated high antitrombogenic activity varying in the range of 10.22-17.67 blood clotting indexes. Therefore, these materials can be used as drug carriers, and tested for a model drug, sodium diclofenac (SDF) that can be released from HA/PEI cryogel composites with a linear fashion with long term releasing capabilities up to 9.22 mg/g within 20 h at physiological conditions, pH 7.4, 37.5 degrees C
Mortality prediction ability of phycians in intensive care units of Turkey (MOPAP)
No full textKUCUK, Ahmet Oguzhan/0000-0002-6993-0519; Yalcinsoy, Murat/0000-0003-3407-7359; KUCUK, Mehtap PEHLIVANLAR/0000-0003-2247-4074; Sahiner, Yeliz/0000-0002-5377-3870Introduction: Intensive care physicians are increasingly involved in decision making about the prognosis of intensive care unit ICU patients. With this study; we aimed to evaluate the power of clinician foresight at prediction of mortality in patient at triage to intensive care and patient follow-up. Materials and Methods: This study was conducted in ICUs located in various geographical regions of Turkey between January 1, 2017-April 30, 2017. The clinical research was planned as observational, multicenter, cross-sectional. Results: A total of 1169 intubated patients were followed in 37 different ICU. At the beginning of the follow-up we asked the physician who will follow the patient in the ICU to give a score for the probability of survival of the patients. Scoring included a total of 6 scores from 0 to 5, with the "0" the worst probability "5" being the best. According to this distribution, only 1 (0.9%) of 113 patients who were given 0 points survived. Three (6.1%) of 49 with the best score of 5 died. Survival rates were significantly different in each score group (r: -0.488; p< 0.001). After the combined mortality estimation scores based on the clinical observations of the physicians (0 and 1 point score was combined as non-survive, 4 and 5 score was combined as survived) 320 of the 545 patients were estimated to be dead and 225 were predicted survival. Sensitivity and spesifity of scoring system to predict mortality was 91.56% (95% Cl: 87.96-94.37), 76.89% (95% CI: 70.82-82.23) respectively. Conclusion: In this study, we concluded that the physicians who follow the patients in the ICU can predict the poor prognosis at the time of admission and the high mortality rate. The physician's opinion on mortality estimation should be considered in intensive care mortality scoring in addition to other laboratory and clinical parameters
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