Browsing by Author "Ceter T."

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A new pollen-derived microcarrier for pantoprazole delivery
(2017-02-01) Akyuz L.; Sargin I.; Kaya M.; Ceter T.; Akata I.
Plant-derived carriers have emerged as promising materials for drug encapsulation. Especially, sporopollenin microcapsules extracted from diverse pollen species have been proved to be effective drug carriers due to their biocompatibility, homogeneity in size, resistance to harsh chemical conditions and high thermal stability. Here in this study, sporopollenin microcapsules were isolated successfully from the pollens of a common tree (Corylus avellana, the European hazelnut) and used as a carrier for pantoprazole (PaNa) (a proton pump inhibitor). The drug entrapment efficiency was recorded as 29.81%. SEM micrographs clearly showed the drug was loaded into the microcapsules through the apertures of microcapsule and also some drugs were adsorbed on the surface of microcapsules. FT-IR spectra analysis confirmed the drug loading. Thermogravimetric analysis revealed that thermal stability of PaNa was enhanced by encapsulation. In vitro release studies showed that PaNa-loaded sporopollenin microcapsules exhibited better release performance than the control. C. avellana sporopollenin microcapsules can make an efficient carrier for delivery of PaNa.
Comparative pollen morphology of annual Trigonella L. (Fabaceae) in Turkey
(2014-04-01) Pinar N.M.; Akan H.; Ceter T.; Aytac Z.; Ekici M.; Acar A.; Akdogan S.
Pollen morphology of 38 Trigonella species was investigated with light microscopies and scanning electron microscopies. Pollen slides were prepared using Wodehouse technique. The pollen grains of Trigonella members are radially symmetrical and isopolar, their outlines are oblong in equatorial view and circular in polar view. Amb is semicircular. The pollen grains are prolate-spheroidal, oblate-spheroidal, suboblate, spheroidal, and prolate with the polar axes 13.5-49.9 μm and the equatorial axes 10.4-43.7 μm. The smallest dimensions are observed in T. spinosa and T. brachycarpa, and the largest in T. carica and T. rhytidocarpa. The pollen grains of Trigonella taxa are usually tricolporate or rarely tricolpate, pantocolporate, tetracolporate, and tricolpodiporate. Various ornamentation types were observed: Microreticulate (section Samaroideae, Pectinatae, Falcatulae, Cylindricae, Bucerates, Reflexae, Isthmocarpae, Capitatae and Foenum-graecum), rugulate-scabrate (section Lunatae, Uncinatae), perforate (T. halophila, T. rigida and T. carica from section Bucerates) and retipilatae (section Biebersteinianae) at equator region and psilate-perforate (section Samaroideae, Pectinatae, Bucerates, Reflexae, Isthmocarpae, Foenum-graecum, T. coelesyriaca, T. cilicica), rugulate-scabrate (section Lunatae, Uncinatae), microreticulate (Falcatulae, Cylindricae and Foenum-graecum) and retipilatae (section Biebersteinianae) at polar region. Ornamentations, pollen shape and the aperture type have been observed as important morphological characters. © 2013 Springer-Verlag Wien.
Controlled release and anti-proliferative effect of imatinib mesylate loaded sporopollenin microcapsules extracted from pollens of Betula pendula
(2017-12-01) Sargin I.; Akyuz L.; Kaya M.; Tan G.; Ceter T.; Yildirim K.; Ertosun S.; Aydin G.H.; Topal M.
Sporopollenin is a promising material for drug encapsulation due to its excellent properties; uniformity in size, non-toxicity, chemically and thermally resilient nature. Herein, morphologically intact sporopollenin microcapsules were extracted from Betula pendula pollens. Cancer therapeutic agent (imatinib mesylate) was loaded into the microcapsules. The encapsulation efficiency by passive loading technique was found to be 21.46%. Release behaviour of the drug from microcapsules was found to be biphasic, with an initial fast release followed by a slower rate of release. Imatinib mesylate release from the drug itself (control) was faster than from imatinib mesylate-loaded sporopollenin microcapsules. The release profiles for both free and entrapped drug samples were significantly slower and more controlled in PBS buffer (pH 7.4) than in HCl (pH 1.2) buffer. Cumulative drug release from IM-MES-loaded sporopollenin microcapsules was found to be 65% within 24 h for PBS, whereas release from the control was completed within 1 h. Also, a complete dissolution of control in HCl buffer was observed within first 30 min. MTT assay revealed that drug-loaded microcapsules were effective on WiDr human colon carcinoma cell line. B. pendula sporopollenin can be suggested as an effective carrier for oral delivery of imatinib mesylate.
Design and application of sporopollenin microcapsule supported palladium catalyst: Remarkably high turnover frequency and reusability in catalysis of biaryls
(2017-01-15) Baran T.; Sargin I.; Kaya M.; Menteş A.; Ceter T.
Bio-based catalyst support materials with high thermal and structural stability are desired for catalysts systems requiring harsh conditions. In this study, a thermally stable palladium catalyst (up to 440 °C) was designed from sporopollenin, which occurs naturally in the outer exine layer of pollens and is widely acknowledged as chemically very stable and inert biological material. Catalyst design procedure included (1) extraction of sporopollenin microcapsules from Betula pendula pollens (∼25 μm), (2) amino-functionalisation of the microcapsules, (3) Schiff base modification and (4) preparation of Pd(II) catalyst. The catalytic activity of the sporopollenin microcapsule supported palladium catalyst was tested in catalysis of biaryls by following a fast, simple and green microwave-assisted method. We recorded outstanding turnover number (TON: 40,000) and frequency (TOF: 400,000) for the catalyst in Suzuki coupling reactions. The catalyst proved to be reusable at least in eight cycles. The catalyst can be suggested for different catalyst systems due to its thermal and structural durability, reusability, inertness to air and its eco-friendly nature.
Fruit structure of 12 Turkish endemic Tripleurospermum Sch. Bip. (Asteraceae) taxa and its taxonomic implications
(2012-04-01) Inceer H.; Bal M.; Ceter T.; Pinar N.
This study concerns the evaluation of micromorphological and anatomical characters of fruit (achene-cypsela) in 12 Turkish endemic Tripleurospermum taxa using multivariate analyses (cluster analysis, principal component analysis, one-way analysis of variance). Pericarp in all taxa examined is mainly composed of several layers of parenchymatous and sclerenchymatous cells with one vascular bundle in each rib. In the achene, the thickness and width of lateral and adaxial ribs with presence or absence of a slime envelope have high taxonomic value for Tripleurospermum at interspecific levels. The slime envelope formation is also correlated with ploidy levels and habitats of some taxa in Tripleurospermum. © 2012 Springer-Verlag.
Incorporation of sporopollenin enhances acid–base durability, hydrophobicity, and mechanical, antifungal and antioxidant properties of chitosan films
(2017-03-25) Kaya M.; Akyuz L.; Sargin I.; Mujtaba M.; Salaberria A.M.; Labidi J.; Cakmak Y.S.; Koc B.; Baran T.; Ceter T.
Sporopollenin-chitosan blend films were produced for the first time. Sporopollenin is a robust structural component of plant pollens exhibiting excellent features such as nontoxicity, biodegradability, biocompatibility, high thermal stability, durability to strong acid and base solutions and homogeneity in size. To benefit from these advantages, sporopollenin samples obtained from Betula pendula (silver birch) were incorporated into chitosan film at different concentration; 10, 20 and 40 mg in 100 mL chitosan gel (1%). Stereo microscopy, FT-IR and TG/DTG analyses showed that sporopollenin was successfully incorporated into the chitosan matrix. Incorporation of sporopollenin in gradually increasing amount into chitosan films was found advantageous in (1) enhancement in chemical durability of the films, (2) increment of hydrophobicity, (3) boosting the mechanical properties, (4) improvement of antifungal and (5) antioxidant activities. This study revealed that sporopollenin can be suggested as an effective blend material for biodegradable edible chitosan film production.
Newly isolated sporopollenin microcages from Platanus orientalis pollens as a vehicle for controlled drug delivery
(2017-08-01) Mujtaba M.; Sargin I.; Akyuz L.; Ceter T.; Kaya M.
Sporopollenin microcages were produced from the pollens of Platanus orientalis. Paracetamol was loaded into the microcages. Pollen, sporopollenin, paracetamol and paracetamol-loaded sporopollenin microcages were characterized with FT-IR, TGA and SEM. The analytical analyses demonstrated that sporopollenin microcages were structurally intact, highly reticulated and thermally stable. The loading efficiency of the sporopollenin microcages was found to be 8.2% using the passive loading technique and 23.7% via evaporating loading technique. In vitro release and kinetics studies were performed to test the suitability of sporopollenin microcages for loading. These studies revealed that sporopollenin from P. orientalis can be suggested as a suitable carrier for drug loading and controlled release studies.
Pollen morphology of Astragalus L. section Hololeuce Bunge (Fabaceae) in Turkey
(2013-01-01) Ceter T.; Ekici M.; Pinar N.; Ozbek F.
Pollen morphology of 15 taxa belonging to the section Hololeuce Bunge of genus Astragalus L. species was investigated by light microscopy and scanning electron microscopy. Pollen slides were prepared using a Wodehouse technique. Measurements were based on 20 or more pollen grains per specimen. For scanning electron microscopy studies, dried pollen grains were transferred on aluminium stubs and coated with gold for 4 min in a sputter-coater. The pollen grains of Hololeuce taxa are radially symmetric and isopolar. The pollen grains of the taxa are prolate–spheroidal, subprolate or prolate with the polar axes 21.42–32.93 μm and the equatorial axes 17.13–28.26 μm. The pollen grains are operculate and trizonocolporate. Syncolporate. Colpi were usually long and narrow (Clt: 4.13–6.68 μm, Clg: 16.56–26.52μm), subterminal, membrane granulate or verrucate. Pores were found to be longate or circular (Plg: 5.01–7.82 μm, Plt: 5.31–8.69 μm). Operculum membrane ornamentation verrucate, granulate, rugulate and reticulate. Pollen grains show reticulate, perforate polar section and perforate, reticulate, microreticulate, perforate–granulate, microreticulate–perforate, microrugulate–perforate, microrugulate–microreticulate, granulate–perforate, microreticulate–granulate at meridional sections. Exine is subtectate and has a thickness of 1.08–1.30 μm. Ectexine is thicker than endexine. Intine has a thickness of 0.5–0.68 μm. As result of this study some pollen characteristic as pollen shape, aperture type and ornamentations are shown to vary within the section Hololeuce. Especially pollen surface ornamentation on polar section and meridional section has systematic value to distinguish taxa from each other. © 2013, Société botanique de France.
Pollen morphology of the genus oxytropis DC. in Turkey
(2013-01-01) Ceter T.; Erkul S.K.; Aytac Z.; Baser B.
Pollen morphology of 11 species of the genus Oxytropis DC. (Fabaceae) distributed in Turkey were examined with light (LM) and scanning electron microscope (SEM). Morphology of pollen grains shows isopolar, radially symmetric, tricolporate, prolate or subprolate, porus shape oblate or operculate and exine subtectate. The size varies with the polar axis from 19.52 - 33.31 μm and the equatorial axis from 13.50 - 25.82 μm. There are five ornamentation types: perforate at equatorial section and psilate at polar sections, microreticulate at equatorial sections and psilate at polar sections, microreticulate at equatorial sections and perforate at polar sections, microreticulate at both equatorial and polar sections and perforate at both equatorial and polar sections. Pollen aperture, shape and especially different ornamentation patterns at polar and equatorial section of pollen, as found in this study, appear to be important character. The findings of this study indicate the taxonomic implications of pollen morphology in understanding the similarity and relationships in the genus Oxytropis.
Preparation and characterisation of biodegradable pollen-chitosan microcapsules and its application in heavy metal removal
(2015-02-01) Sargin I.; Kaya M.; Arslan G.; Baran T.; Ceter T.
Biosorbents have been widely used in heavy metal removal. New resources should be exploited to develop more efficient biosorbents. This study reports the preparation of three novel chitosan microcapsules from pollens of three common, wind-pollinated plants (Acer negundo, Cupressus sempervirens and Populus nigra). The microcapsules were characterized (Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis) and used in removal of heavy metal ions: Cd(II), Cr(III), Cu(II), Ni(II) and Zn(II). Their sorption capacities were compared to those of cross-linked chitosan beads without pollen grains. C. sempervirens-chitosan microcapsules exhibited better performance (Cd(II): 65.98; Cu(II): 67.10 and Zn(II): 49.55mgg-1) than the other microcapsules and the cross-linked beads. A. negundo-chitosan microcapsules were more efficient in Cr(III) (70.40mgg-1) removal. P. nigra-chitosan microcapsules were found to be less efficient. Chitosan-pollen microcapsules (except P. nigra-chitosan microcapsules) can be used in heavy metal removal.