title: New approach for local cancer treatment using pulsed high-intensity focused ultrasound and phase-change nanodroplets.
abstract: OBJECTIVE
  The aim of this study was to investigate the combination effects of pulsed HIFU (pHIFU) and phase-change nanodroplets (PCND) as a sensitizer on efficient induction of mechanical effects of pHIFU and chemically enhanced tumor growth inhibition for local anti-tumor therapy.
  
  
  METHODS
  Changes in growth of colon 26 tumor tissue inoculated onto CDF1 mice were evaluated by the following treatments. (1) pHIFU exposure (1.1 MHz, 3.2 kW/cm(2), 300 cycles, and 50 ms interval) for 60 s, (2) PCND (1 %) injection, (3) adriamycin (4 mg/kg) injection, (4) pHIFU exposure after PCND injection, and (5) pHIFU exposure after PCND + adriamycin injection simultaneously.
  
  
  RESULTS
  Significant changes in tumor growth were observed in the group with combination of pHIFU and PCND, although single therapy did not show any significant difference. PCND enhanced mechanical tissue fractionation by pHIFU, which was detectable by Real-time tissue elastography. Moreover, the combination of pHIFU and PCND + Adriamycin suppressed the tumor growth for 2 weeks, and 3 of 4 mice did not show any sign of regrowth during the 30-day observation.
  
  
  CONCLUSIONS
  The combination of pHIFU and PCND exerted a significant anti-tumor effect and may be a new candidate for treatment of locally advanced cancer.
authors.affiliation: Department of Cancer Survey and Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Ashida
authors.affiliation: Research & Development Group, Hitachi, Ltd., 1-280 Higashi Koigakubo, Kokubunji, Tokyo, 180-8601, Japan. kenichi.kawabata.ap@hitachi.com.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Kawabata
authors.affiliation: Research & Development Group, Hitachi, Ltd., 1-280 Higashi Koigakubo, Kokubunji, Tokyo, 180-8601, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Maruoka
authors.affiliation: Research & Development Group, Hitachi, Ltd., 1-280 Higashi Koigakubo, Kokubunji, Tokyo, 180-8601, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Asami
authors.affiliation: Research & Development Group, Hitachi, Ltd., 1-280 Higashi Koigakubo, Kokubunji, Tokyo, 180-8601, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.affiliation: Department of Cancer Prevention, Osaka Center for Cancer and Cardiovascular Diseases Prevention, Osaka, Japan.
authors.forename: Rena
authors.initials: R
authors.lastname: Takakura
authors.affiliation: Department of Cancer Survey and Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ioka
authors.affiliation: Department of Cancer Survey and Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Katayama
authors.affiliation: Department of Cancer Prevention, Osaka Center for Cancer and Cardiovascular Diseases Prevention, Osaka, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D057086:High-Intensity Focused Ultrasound Ablation; D008297:Male; D051379:Mice; D036103:Nanotechnology; D009369:Neoplasms / Q000628:therapy*
keywords: Cancer; Drug delivery system; HIFU; Histotripsy; Mechanical effect; Superheated perfluorocarbon droplet