Role of frequency and mechanical index in ultrasonic-enhanced chemotherapy in rats

Abstract

Application of ultrasound in combination with drug therapy was effective in reducing tumor growth rate, irrespective of which frequency was employed.

Preliminary Results of Combining Low Frequency Low Intensity Ultrasound and Liposomal Drug Delivery to Treat Tumors in Rats

“…Our previous work with Dox-containing micelles showed that reduced growth was observed at a wide range of frequencies, 20, 70 and 500 kHz, suggesting that, at least with micelles, frequency is a parameter of lesser importance. 5 While it might be possible that when using liposomes the difference between our positive results in tumor regression and the less positive results of others is due solely to frequency, we do not have sufficient data at present to make such a claim.…”

“…Similar experiments employing Dox-loaded micelles (at 2.67 mg/kg) produced a slight but statistically significant reduction in tumor growth rate at 476 kHz, from 0 038 ± 0 007 per day to 0 032 ± 0 013 per day. 5 The therapeutic results with micelles were much less pronounced than the results in which stealth liposomes were employed.…”

“…activity is independent of acoustic frequency as long as the combination of frequency and power density produces a similar intensity of inertial cavitation. 5 In this paper we report even better in vivo results when using a liposomal drug carrier in combination with low frequency ultrasound. A liposome is a vesicle composed of a surfactant bilayer enveloping an aqueous interior.…”

Sonosensitive theranostic liposomes for preclinical in vivo MRI-guided visualization of doxorubicin release stimulated by pulsed low intensity non-focused ultrasound

“…Furthermore, the therapeutic benefit of this approach has been pre-clinically validated on tumor murine models [42,49,50].…”

The Use of Ultrasound and Micelles in Cancer Treatment

“…Staples also compared Dox bio-distribution in several organs at different times after the rats were treated with a combination of Dox/ Plurogel™/US (89,96). In spite of the slower growth of tumors receiving US/Dox/ compared to Dox/Plurogel™ without US, their study found that shortly after injection and ultrasonic exposure, the insonated tumors contained slightly more Dox than the contra lateral control tumors.…”