Browsing by Author "Zimmerman, R"

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    Ion implantation inhibits cell attachment to glassy polymeric carbon
    (ELSEVIER SCIENCE BV) 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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    The influence of ion implantation on cell attachment to glassy polymeric carbon
    (AMER INST PHYSICS) 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.
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    Enhanced biocompatibility of GPC by ion implantation and deposition
    (ELSEVIER SCIENCE SA) Zimmerman, R; Gürhan, I; Muntele, C; Ila, D; Rodrigues, M; Özdal-Kurt, F; Sen, BH
    Biocompatible Glassy Polymeric Carbon (GPC) is used for artificial heart valves and in other biomedical applications. Although it is ideally suited for implants in the blood stream, tissue that normally forms around the moving parts of a GPC heart valve sometimes loses adhesion and creates embolisms downstream. We have previously shown that oxygen ion implantation slightly enhances cell adhesion to GPC. Here we compare silver ion implantation and silver deposition, each of which strongly inhibits cell attachment on GPC. Inhibition of cell adhesion is the more desirable improvement to current GPC cardiac implants. In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that traces of silver can favorably influence the surface of GPC for biomedical applications. (c) 2007 Published by Elsevier B.V.
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    Investigation of cell growth on ion beam patterns on GPC surface
    (ELSEVIER SCIENCE SA) 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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    Modification of surface morphology of UHMWPE for biomedical implants
    (MATERIALS RESEARCH SOC) Oztarhan, A; Urkac, ES; Kaya, N; Yenigul, M; Tihminlioglu, F; Ezdesir, A; Zimmerman, R; Budak, S; Muntele, C; Chhay, B; Ila, D; Oks, E; Nikolaev, A; Tek, Z; Eltem, R
    Ultra High Molecular Weight Polyethylene (UHMWPE) samples were implanted with metal and metal-gas hybrid ions (Ag, Ag+N, C+H, C+H+Ar, Ti+O) by using improved MEVVA Ion implantation technique [1,2]. An extraction voltage of 30 kV and influence of 1017 ions/cm2 were attempted in this experiment. to change their surface morphologies in order to understand the effect of ion implantation on the surface properties of UHMWPEs. Characterizations of the implanted samples with RBS, ATR - FTIR, spectra were compared with the un-implanted ones. Implanted and unimplanted samples were also thermally characterized by TGA and DSC. It was generally observed that C-H bond concentration seemed to be decreasing with ion implantation and the results indicated that the chain structure of UHMWPE were changed and crosslink density and polymer crystallinity were increased compared to unimplanted ones resulting in increased hardness. It was also observed that nano size cracks (approx. 10nm) were significantly disappeared after Ag implantation, which also has an improved antibacterial effect. Contact angle measurements showed that wettability of samples increased with ion implantation. Results showed that metal and metal+gas hybrid ion implantation could be an effective way to improve the surface properties of UHMWPE to be used in hip and knee prosthesis.