立花 克郎, 入江 豊, 小川 皓一

Katsuro TACHIBANA, Yutaka IRIE, Koichi OGAWA

福岡大学医学部解剖学教室

Department of Anatomy, Fukuoka University School of Medicine

キーワード : therapy, cancer, gene therapy, microbubble , drug

近年, 超音波治療に関する研究が飛躍的に進歩した. 中でも薬物治療と超音波エネルギーを併用する新しい試みがなされ,薬物の効果促進作用が多く報告されている. 特に注目されているのは超音波の血栓溶解療法や遺伝子治療への応用である. また, 超音波造影剤(マイクロバブル) を利用することで細胞内へ遺伝子を容易に導入できることも発見され, 様々な分野における超音波とマイクロバブルの組み合わせが期待されている. 治療用超音波の照射によってマイクロバブルの崩壊を時間的, 空間的に制御できるので, バブル内に封入した薬物や遺伝子の局所リリースに応用されようとしている. この研究で動脈硬化, 腫瘍, 血管狭窄部位への遺伝子導入が最も進歩している.

Therapeutic ultrasound has been used mainly for its thermal or mechanical effects. Medical applications of high-energy nonthermal ultrasound to ablate cancers are now being studied. Reports reveal that many diseases are being treated with a combination of ultrasound and drugs. Further, the introduction of microbubbles and nanobubbles to carry and enhance drugs has added a new dimension to therapeutic ultrasound. Pharmaceutical agents developed during the past decade have markedly increased the promise of this technology for molecular biology, gene therapy, and regenerative medicine. Similar promise is offered by the development of new devices: therapeutic ultrasound catheters and extracorporeal ultrasound probes, for example, are being developed, and some are undergoing clinical trials. Advances like use of ultrasound to enhance the effects of thrombolytic agents have proven beneficial in treating patients with acute stroke and occlusion of peripheral arteries. Noninvasive focused ultrasound in conjunction with anticancer drugs may help to reduce tumor size, probability of recurrence, and severity of drug side effects. Last, advances in molecular imaging offer increased promise for both diagnostic and therapeutic ultrasound. Microbubbles or nanobubbles targeted at the molecular level will enable physicians to make a definite diagnoses with diagnostic ultrasound and then proceed immediately to use ultrasound therapeutically.