Katsuro Tachibana1, Hitomi Endo2, Loreto B Feril2, Seyedeh Moosavi Nejad2, Hiromasa Takahashi3,4, Kyoichi Narihira3, Toshihiro Kikuta3. 1. Department of Anatomy, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan, Fukuoka, 814-0180, Japan. k-tachi@fukuoka-u.ac.jp. 2. Department of Anatomy, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan, Fukuoka, 814-0180, Japan. 3. Department of Oral Surgery, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan, Fukuoka, 814-0180, Japan. 4. Department of Dentistry, Self Defense Forces Kure Hospital, 6-34, Showa, Kure, Hiroshima, 737-0027, Japan.
Abstract
PURPOSE: To evaluate in vitro the feasibility of therapeutic high-intensity-focused ultrasound (HIFU) combined with microbubbles and titanium dioxide (TiO2). METHODS: Oral squamous cell carcinoma cells (HSC-2) were sonicated using a HIFU transducer with a resonant frequency of 3.5 MHz, 30 mm in diameter, and focal length of 50 mm. The ultrasound intensity was 210 W/cm(2), and two pulses (0.5 s each) were sonicated for each cell sample (9 × 10(4) cells per well). Immediately after HIFU, the viable cells were measured by an automated cell counter. The survival rate was measured in the presence of microbubbles (Sonazoid) and peroxo titania-silica (R-P-TS) or anatase titania-silica (R-A-TS) TiO2. RESULTS: Cell viability immediately following sonication in the presence of TiO2 (R-A-TS) and TiO2 (R-P-TS) was 65.5 ± 0.7 and 59.4 ± 3.3 %, respectively. A marked decrease in cell viability was seen when microbubbles were added to the above cell conditions. Specifically, cell viability decreased to 14.0 ± 0.1 and 4.4 ± 0.9 % when microbubbles were added to samples containing TiO2 (R-A-TS) and TiO2 (R-P-TS), respectively. CONCLUSION: Immediate in vitro cell killing was observed with short pulsed duration HIFU sonication with a combination of microbubbles and TiO2. This finding suggests that TiO2 could have caused enhanced mechanical cell destruction by microbubbles.
PURPOSE: To evaluate in vitro the feasibility of therapeutic high-intensity-focused ultrasound (HIFU) combined with microbubbles and titanium dioxide (TiO2). METHODS: Oral squamous cell carcinoma cells (HSC-2) were sonicated using a HIFU transducer with a resonant frequency of 3.5 MHz, 30 mm in diameter, and focal length of 50 mm. The ultrasound intensity was 210 W/cm(2), and two pulses (0.5 s each) were sonicated for each cell sample (9 × 10(4) cells per well). Immediately after HIFU, the viable cells were measured by an automated cell counter. The survival rate was measured in the presence of microbubbles (Sonazoid) and peroxo titania-silica (R-P-TS) or anatase titania-silica (R-A-TS) TiO2. RESULTS: Cell viability immediately following sonication in the presence of TiO2 (R-A-TS) and TiO2 (R-P-TS) was 65.5 ± 0.7 and 59.4 ± 3.3 %, respectively. A marked decrease in cell viability was seen when microbubbles were added to the above cell conditions. Specifically, cell viability decreased to 14.0 ± 0.1 and 4.4 ± 0.9 % when microbubbles were added to samples containing TiO2 (R-A-TS) and TiO2 (R-P-TS), respectively. CONCLUSION: Immediate in vitro cell killing was observed with short pulsed duration HIFU sonication with a combination of microbubbles and TiO2. This finding suggests that TiO2 could have caused enhanced mechanical cell destruction by microbubbles.
Authors: Tykhon Zubkov; Dirk Stahl; Tracy L Thompson; Dimitar Panayotov; Oliver Diwald; John T Yates Journal: J Phys Chem B Date: 2005-08-18 Impact factor: 2.991