Selective Ablation of Cancer Cells with Low Intensity Pulsed Ultrasound

Ultrasound can be focused into deep tissues with millimeter precision to perform noninvasive ablative therapy for diseases such as cancer. In most cases, this ablation uses high-intensity ultrasound to deposit nonselective thermal or mechanical energy at the ultrasound focus, damaging both healthy bystander tissue and cancer cells. Here, we describe an alternative low intensity (I_(SPTA) < 5 W/cm²) pulsed ultrasound approach that leverages the distinct mechanical properties of neoplastic cells to achieve inherent cancer selectivity. We show that ultrasound applied at a frequency of 0.5–0.67 MHz and a pulse duration of >20 ms causes selective disruption of a panel of breast, colon, and leukemia cancer cell models in suspension without significantly damaging healthy immune or red blood cells. Mechanistic experiments reveal that the formation of acoustic standing waves and the emergence of cell-seeded cavitation leads to cytoskeletal disruption, expression of apoptotic markers, and cell death. The inherent selectivity of this low-intensity pulsed ultrasound approach offers a potentially safer and thus more broadly applicable alternative to nonselective high-intensity ultrasound ablation.

Mittelstein, David R et al

 Applied Physics Letters, (2020), 116 (1). Art. No. 013701. ISSN 0003-6951.

Low-frequency mechanical vibration induces apoptosis of A431 epidermoid carcinoma cells

Cancer research is increasingly focused on discovering strategies to induce cancer cell apoptosis without affecting surrounding normal cells. One potential biocompatible method is mechanical vibration, which has been developed as part of the emerging field of mechanomedicine. Previous studies of mechanical vibration have employed high-frequency vibration, which damages healthy cells. In this study, we examined the effects of brief (1 h) low-frequency (20 Hz) mechanical vibration on glucose consumption and survival (apoptosis, necrosis, HMGB1 release) of the human epidermoid carcinoma cell line A431. We found that apoptosis, but not necrosis, was significantly increased at 48 h after mechanical vibration compared with cells maintained in static culture. In keeping with this, extracellular release of HMGB1, a necrosis marker, was lower in cultures of A431 cells subjected to mechanical vibration compared with control cells. Glucose consumption was increased in the first 24 h after mechanical vibration but returned to control levels before the onset of apoptosis. Although the precise intracellular mechanisms by which low-frequency mechanical vibration triggers apoptosis of A431 cells is unknown, these results suggest a possible role for metabolic pathways. Mechanical vibration may thus represent a novel application of mechanomedicine to cancer therapy.

Engineering in Life Sciences Journal
First published: 27 February 2020

Effects of Focused Vibrations on Human Satellite Cells

Skeletal muscle consists of long plurinucleate and contractile structures, able to regenerate and repair tissue damage by their resident stem cells: satellite cells (SCs). Reduced skeletal muscle regeneration and progressive atrophy are typical features of sarcopenia, which has important health care implications for humans. Sarcopenia treatment is usually based on physical exercise and nutritional plans, possibly associated with rehabilitation programs, such as vibratory stimulation. Vibrations stimulate muscles and can increase postural stability, balance, and walking in aged and sarcopenic patients. However, the possible direct effect of vibration on SCs is still unclear. Here,
we show the effects of focused vibrations administered at increasing time intervals on SCs, isolated from young and aged subjects and cultured in vitro. After stimulations, we found in both young and aged subjects a reduced percentage of apoptotic cells, increased cell size and percentage of aligned cells, mitotic events, and activated cells. We also found an increased number of cells only in young samples. Our results highlight for the first time the presence of direct effects of mechanical vibrations on human SCs. These effects seem to be age-dependent, consisting of a proliferative response of cells derived from young subjects vs. a differentiative response of cells from aged subjects.

Silvia Sancilio et al

international journal of molecular sciences

Cancer treatment by magneto-mechanical effect of particles, a review

Cancer treatment by magneto-mechanical effect of particles (TMMEP) is a growing field of research. The principle of this technique is to apply a mechanical force on cancer cells in order to destroy them thanks to magnetic particles vibrations. For this purpose, magnetic particles are injected in the tumor or exposed to cancer cells and a low-frequency alternating magnetic field is applied. This therapeutic approach is quite new and a wide range of treatment parameters are explored to date, as described in the literature. This review explains the principle of the technique, summarizes the parameters used by the different groups and reports the main in vitro and in vivo results.

Cécile Naud et al

The Royal Society of Chemistry 2020

DOI: 10.1039/D0NA00187B

Effect of whole-body vibration on muscle strength, spasticity, and motor performance in spastic diplegic cerebral palsy children


Background and purpose

Spastic diplegia is a common form of cerebral palsy (CP) and is characterized by spasticity and muscle weakness of both lower limbs resulting in decreased walking ability. The purpose of this study was to evaluate the effect of whole body vibration (WBV) training on muscle strength, spasticity, and motor performance in spastic diplegic cerebral palsy children after 12-weeks treatment.


Thirty spastic diplegic CP children (8–12 years) were randomized to two equal groups, control group and WBV group. The control group received a selected physical therapy treatment program for spastic diplegic CP and the WBV group received the same program in addition to WBV training. Measurements of isometric strength of knee extensors, spasticity, walking speed, walking balance and gross motor function were performed before and after 12 weeks of the treatment program.


Isometric strength of knee extensors, spasticity and the walking speed were significantly improved only in the WBV group (P < 0.05). Growth motor function measure-88 (GMFM-88) (D%) was significantly increased (P < 0.05) in both groups in favor of the WBV group and GMFM-88 (E%) was significantly increased (P < 0.05) only in the WBV group, while walking balance did not change significantly in either group.


The obtained results suggest that 12-weeks’ intervention of whole-body vibration training can increase knee extensors strength and decrease spasticity with beneficial effects on walking speed and motor development in spastic diplegic CP children.

Marwa M.Ibrahim Mohamed A.Eid Samah A.Moawd

Egyptian Journal of Medical Human Genetics

Volume 15, Issue 2, April 2014, Pages 173-179