title: Active control of microcapsules in artificial blood vessel by producing local acoustic radiation force.
abstract: Micrometer-sized microcapsules collapse upon exposure to ultrasound. Use of this phenomenon for a drug delivery system (DDS), not only for local delivery of medication but also for gene therapy, should be possible. However, enhancing the efficiency of medication is limited because capsules in suspension diffuse in the human body after injection, since the motion of capsules in blood flow cannot be controlled. To control the behavior of microcapsules, acoustic radiation force was introduced. We detected local changes in microcapsule density by producing acoustic radiation force in an artificial blood vessel. Furthermore, we theoretically estimated the conditions required for active path selection of capsules at a bifurcation point in the artificial blood vessel. We observed the difference in capsule density at both in the bifurcation point and in alternative paths downstream of the bifurcation point for different the acoustic radiation forces. Also we confirmed the microcapsules are trapped against flow with the condition when the acoustic radiation force is more than fluid resistance of the capsules. The possibility of controlling capsule flow towards a specific point in a blood vessel was demonstrated.
authors: Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588 Japan. masuda_k@cc.tuat.ac.jp
authors: Kohji
authors: K
authors: Masuda
authors: Ryusuke
authors: R
authors: Nakamoto
authors: Yusuke
authors: Y
authors: Muramatsu
authors: Yoshitaka
authors: Y
authors: Miyamoto
authors: Keri
authors: K
authors: Kim
authors: Toshio
authors: T
authors: Chiba
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000528:radiation effects*; D002214:Capsules / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004339:Drug Compounding / Q000379:methods*; D006801:Humans; D008422:Materials Testing; D011829:Radiation Dosage; D013010:Sonication / Q000379:methods*
chemical_list: D002214:Capsules