Browsing by Author "Ozdal-Kurt, F"

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    Characterization of osteoblasts derived from bone marrow stromal cells in a modified cell culture system
    Deliloglu-Gurhan, SI; Vatansever, HS; Ozdal-Kurt, F; Tuglu, I
    Bone marrow is a complex tissue composed of hematopoietic and stromal. stem cells with the potential to differentiate into adipogenic, fibroblastic, reticular, osteogenic and chondrogenic lineages. Identification of differentiation markers during transformation of stromal cells into osteoblasts in a time-dependent manner may be informative for cell-based tissue engineering. Therefore, we investigated the effects of osteogenic medium (OM) on the proliferation and differentiation of rat bone marrow stromal. cells (BMSCs). BMSCs from adult mate rat tibia and femur were collected and cultured in alpha-MEM medium with 10% fetal bovine serum, penicillin, streptomycin and gentamycin. After three days of culture, the medium covering the adherent cells in culture was changed to OM containing dexamethasone, Na-beta-glycerophosphate and ascorbic acid. As a control., cell. culture was also continued in the original. medium for the same time period. Differentiated osteoblast cells were collected after 7, 10, 14, 21 and 30 days of culture, fixed with 4% paraformaldehyde and their immunolabelling for osteoblast markers osteonectin (ON) and osteocalcin (OC) was assessed using an indirect immunoperoxidase technique. Immunoabelling of ON and OC was detectable from day 10 of culture, began to increase on day 14, and increased steadily through to day 21. Labelling was highest on day 30 and was more intense in cells cultured with OM compared to the culture without OM. The control cells cultured in the absence of OM produced negligible levels of both markers. In conclusion, our culture system facilitated differentiation of BMSCs into osteoblasts featuring osteoblast markers, and these cells may be useful in autologous bone implant for the treatment of bone wound heating. (C) 2005 Elsevier GmbH. All rights reserved.
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    Propolis from Turkey induces apoptosis through activating caspases in human breast carcinoma cell lines
    Vatansever, HS; Sorkun, K; Gurhan, SID; Ozdal-Kurt, F; Turkoz, E; Gencay, O; Salih, B
    Propolis is a sticky substance that is collected from plants by honeybees that has anti-mutagenic and anti-carcinogenic properties with biological and therapeutic effects The target of this study was to investigate the anti apoptotic effect of propolis extracts (PE) on the caspase pathway in the human breast cell line MCF 7 in culture Seven different propolis extracts, numbered PE 1-7, produced in their natural ecological environment, were collected from the Hacettepe University Beytepe Campus area in Ankara, Turkey Individual extracts at 0 5, 0 25, 0 125 and 0 063 mg/ml were incubated with MCF 7 cells during 2 days culture Cell growth and cytotoxicity were measured colorimetrically by MTT assay Apoptotic cell death was determined by the TUNEL method (terminal deoxynucleotidyltransferase-biotin nick end labelling) and caspase activity was investigated by immunocytochemistry using antibodies directed against caspase 6, caspase 8 and caspase 9 The results showed that the PE 5 and 6 extracts at 0 125 mg/ml dilution induced apoptosis in association with increased number of TUNEL positive cells MTT results showed that cultures exposed to the same extracts and at the same dilution experienced better cell growth compared to those cultures exposed to the other extracts Immunpositivity for all caspases was detected after treatment with all the extracts and at all dilutions, with stronger immunoreactivity for caspase 6 than caspases 8 and 9 Caspase 6 labelling was especially strong in PE 5 and PE 6 We conclude that propolis may have anti-tumour effects by increasing apoptosis through the caspase pathway Such propolis extracts may be important economically and allow development of a relatively inexpensive cancer treatment (C) 2009 Elsevier GmbH All rights reserved
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    Investigation of cell growth on ion beam patterns on GPC surface
    Zimmerman, R; Muntele, C; Gurhan, I; Ozdal-Kurt, F; Sen, BH; Rodrigues, M; Ila, D
    We have used implanted silver ions near the surface of Glassy Polymeric Carbon (GPC) to completely inhibit cell attachment and adhesion to GPC. The effect improves the safety and function of the GPC heart valve exposed to the blood stream. The strength, durability and low density make GPC a favored material for in vivo medical applications, including transcutaneous electrodes and replacement heart valves. However, the possible release of endothelial tissue that forms on the smooth surfaces of the GPC heart valve has the potential of creating an embolism. We have shown that L929 endothelial cells avoid silver implanted areas of GPC but attach and strongly adhere to areas close to silver implanted surfaces. Patterned ion implantation permits precise control of tissue growth on GPC and other biocompatible substrates. Cell growth inhibited by silver ion implanted patterns on an otherwise biocompatible substrate may be useful for in vitro studies of the way that cells sense and move away from inhospitable environments. (C) 2009 Published by Elsevier B.V.
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    Ion implantation inhibits cell attachment to glassy polymeric carbon
    Zimmerman, R; Deliloglu-Gurhan, I; Ozdal-Kurt, F; Sen, BH; Rodrigues, M; Ila, D
    Implantation of MeV gold, oxygen, carbon ions into GPC alters the surface topography of GPC and enhances the already strong tendency for cells to attach to GPC. We have shown that implantation of silver ions near the surface strongly inhibits cell growth on GPC. Both enhanced adhesion of and inhibition of cell growth are desirable improvements on cardiac implants that have long been successfully fabricated from biocompatible glassy polymeric carbon (GPC). In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that ion beam assisted deposition (IBAD) of silver, as well as silver ion bombardment, can favorably influence the surface of GPC for biomedical applications. (c) 2007 Elsevier B.V. All rights reserved.
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    Neurotoxic effect of Caulerpa racemosa var. cylindracea by neurite inhibition on the neuroblastoma cell line
    Kurt, O; Ozdal-Kurt, F; Tuglu, I; Deliloglu-Gurhan, SI; Ozturk, M
    In the present study, antiproliferative, apoptotic and especially neurotoxic effects of Caulerpa racemosa var. cylindracea dry and wet extracts on mouse neuroblastoma cell line, NA2B were investigated by neurotoxicity screening test (NST). C. racemosa var. cylindracea wet and dry extracts were obtained by methanol (MT) extraction. The effect of the extracts on viability and proliferation was measured by MTT. NA2B cells were induced to differentiate using 1 mu M dcAMP and the amount of inhibition of growing neurites in different dilutions (50, 35, 25, 15, 10 and 5 mu l/ml) by extracts was measured. The number of apoptotic cells was computed by TUNEL method using cells in culture. It was found that majority of the cells died with dry extract above the level of 15 mu l/ml due to the MT effect. Below this level, on the other hand, presence of cell death and antiproliferative effect was noted due to the toxic effects of C. racemosa var. cylindracea which was independent of MT. In all doses of wet extracts, similar but less prominent dose-dependent effects were observed. Below the level of 15 mu l/ml, mild toxic effect presented itself with neurite inhibition. In addition to the toxic, apoptotic and antiproliferative effects of C. racemosa var. cylindracea, its neurotoxic effects possessing property at low concentrations which manifesting itself by neurite inhibition was also showed. This species offers a potential for developing new drugs due to its antiproliferative, toxic and apoptotic effects. Nevertheless, its neurotoxic effect is a factor to be considered as multifunctional agents especially in neuronal metabolism.
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    The influence of ion implantation on cell attachment to glassy polymeric carbon
    Zimmerman, R; Gurhan, I; Ozdal-Kurt, F; Sen, BH; Roigues, M; Ila, D
    In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that near surface implantation of silver in Glassy Polymeric Carbon (GPC) can completely inhibit cell attachment on implanted areas while leaving adjacent areas unaffected. Patterned ion implantation permits precise control of tissue growth on medical applications of GPC. We have shown that silver ion implantation or argon ion assisted surface deposition of silver inhibits cell growth on GPC, a desirable improvement of current cardiac implants.