Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Biomaterials
Abstract number: 23863
IN VITRO ANTAGONIZING EFFECT OF POROUS TANTALUM IMPLANT ON
CYTOTOXICITY OF DOXORUBICIN
Cody BÜNGER, Muwan CHEN, San HEIN, Dang LE, Xuenong ZOU
Aarhus University Hospital, Århus (DENMARK),
Transition metal oxides like titanium dioxide can generate reactive oxygen species
(ROS) and degrade chromophores in organic dyes. The interaction between metal
implants and antineoplastic drugs is important for bone cancer treatment but this has
not been investigated. We aimed to investigate the interaction between porous
tantalum (Ta) implants and a chemotherapeutic drug, Doxorubicin (DOX). Ta
implants were immersed in aqueous DOX solutions, in which rabbit rectal tumor cells
(VX2) were cultured. Cell viability was determined by MTT and the fluorescence of
the DOX chromophore was measured with a spectrofluorometer. ROS formation was
determined using tempo-9-ac and flow cytometry. We observed that 95% of the DOX
fluorescence disappeared when 5 g/mL DOX solution was treated with Ta implant.
However, the addition of antioxidant Dithiothreitol (DTT, 10 g/mL) to the solutions
recovered up to 20.16% of the fluorescence. With UV exposure of the Ta implants,
the solution reduced 98% of the fluorescence and the addition of DTT recovered
4.40% of the fluorescence. In vitro VX-2 cell viability assay showed that the Ta
implants antagonized the cytotoxic effects of DOX. Ta implants in aqueous medium
could produce hydroxyl radicals. We observed higher intracellular ROS activities
when basal medium was incubated with the Ta implant. We concluded that Ta
implants antagonize the cytotoxicity of DOX, mainly by ROS generated from the
porous Ta implant. These results suggest that it is important to consider the
antagonizing effect of the metal implant on DOX in bone cancer patients after
reconstructive surgeries.
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