Abstract 1321: A novel prevention method against re-obstruction of titanium alloy stent for biliary malignancy using generation of hydroxyl radical under ultrasonic irradiation
| Autor: | Tomonori Fujimura, Osamu Itano, Sachiko Matsuda, Minoru Tanabe, Minoru Kitago, Onishi Tatsuya, Yuko Kitagawa, Nobuaki Shimizu, Shigeyuki Kawachi, Chiaki Ogino, Masahiro Shinoda |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | Cancer Research. 72:1321-1321 |
| ISSN: | 1538-7445 0008-5472 |
| Popis: | [introduction] Palliative biliary drainage using a metallic stent is performed for biliary obstruction by unresectable biliary carcinoma.The most important problem of biliary stenting therapy is re-obstruction due to tumor ingrowth. The generation of hydroxyl radical was investigated during ultrasonic irradiation and in the presence of TiO2(Shimizu, etal.Ultrason.Sonochem.2008).The metal stent which is used for biliary drainage is made of titanium alloy, and it is thought that it could generate hydroxyl radicals under ultrasonic irradiation in the same way. The object of this study was to establish a novel prevention method of re-obstruction of the stent using generation of hydroxyl radical under ultrasonic irradiation. [method] {in vitro}Nickel titanium alloy was ultrasonically irradiated at frequency of 1MHz for 30 seconds and the amount of generated hydroxyl radical was measured when intensity was changed to 0.1-0.5 W/cm2 by APF method. To evaluate the cytotoxic effect of the generated radicals, trypan blue exclusion assay was used.The number of living cells were counted. {in vivo}A stent re-obstruction model was established.Nude mice(BALB c nu/nu) were given an injection of 1.0×107 of human squamous carcinoma A431 cells on the back.After Seven days, a stent was put in the neighborhood of tumor.The irradiation group(n=3) was given 10 minutes-ultrasonic irradiation of 0.3W /cm2 once a day.The non-irradiation group(n=3) was not irradiated. Tumors with stents were resected on the 14th day. Tumor ingrowth area was measured and histlogical examination of the tumors was performed. [result] {in vitro}The maximum amount of hydroxyl radical generation was measured under ultrasonic irradiation of 0.3W /cm2. The number of living cells with titanium alloy under ultrasonic irradiation(0.3W /cm2 30seconds) was 79% of that without ultrasonic irradiation. {in vivo}On the 14th day, tumor ingrowth to the stent was seen in the non-irradiation group of the stent re-obstruction model.Tumor ingrowth to the stent was clearly inhibited in the irradiation group. [conclusion] Hydroxyl radical was generated from a titanium alloy stent by ultrasonic irradiation and seemed to have therapeutic efficacy. Tumor ingrowth was inhibited, and preventive effect against re-obstruction was suggested. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1321. doi:1538-7445.AM2012-1321 |
| Databáze: | OpenAIRE |
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