A novel technology described in the journal Nanoscale enables targeted destruction of cancerous tumours, via a combination of ultrasound and the injection of nanobubbles into the bloodstream. Unlike invasive treatment methods or the injection of microbubbles into the tumour itself, this latest technology enables the destruction of the tumour in a non-invasive manner.
Dr Tali Ilovitsh at Tel Aviv University said: “Our new technology makes it possible, in a relatively simple way, to inject nanobubbles into the bloodstream, which then congregate around the cancerous tumour. After that, using a low-frequency ultrasound, we explode the nanobubbles, and thereby the tumour.”
At present, the usual cancer treatment is surgical removal of the tumour, in combination with complementary treatments such as chemotherapy and immunotherapy.
Therapeutic ultrasound to destroy the cancerous tumour is a non-invasive alternative to surgery, a method which comes with advantages and disadvantages. On the one hand, it allows for localised and focused treatment; the use of high-intensity ultrasound can produce thermal or mechanical effects by delivering powerful acoustic energy to a focal point with high spatial-temporal precision. This method has been used to effectively treat solid tumours deep within in the body. Moreover, it makes it possible to treat patients who are unfit for tumour resection surgery. The disadvantage is that the heat and high intensity of the ultrasound waves could cause damage to neighbouring healthy tissues.
Reducing off-target damage
In the current study, Dr Ilovitsh and her team sought to overcome this problem. In the experiment, which used an animal model, the researchers were able to destroy the tumour by injecting nanobubbles into the bloodstream (as opposed to what has been until now, which is the local injection of microbubbles into the tumour itself), in combination with low-frequency ultrasound waves, with minimal off-target effects.
“The combination of nanobubbles and low frequency ultrasound waves provides a more specific targeting of the area of the tumour, and reduces off-target toxicity,” explains Dr Ilovitsh.
“Applying the low frequency to the nanobubbles causes their extreme swelling and explosion, even at low pressures. This makes it possible to perform the mechanical destruction of the tumours at low-pressure thresholds.”
“Our method has the advantages of ultrasound, in that it is safe, cost-effective, and clinically available, and in addition, the use of nanobubbles facilitates the targeting of tumours because they can be observed with the help of ultrasound imaging.”
Dr Ilovitsh adds that the use of low-frequency ultrasound also increases the depth of penetration, minimises distortion and attenuation, and enlarges the focal point. “This can help in the treatment of tumours that are located deep with the body, and in addition facilitate the treatment of larger tumour volumes. The experiment was conducted in a breast cancer tumour lab model, but it is likely that the treatment will also be effective with other types of tumours, and in the future, also in humans.”
Source: Tel Aviv University
