Cancer, a devastating disease, continues to be a leading cause of death in the U.S., second only to heart disease. However, a groundbreaking approach to cancer treatment, developed by researchers at CU Boulder, offers a glimmer of hope. This innovative method utilizes sound waves to soften tumors, potentially revolutionizing the way we combat this deadly disease.
Chemotherapy, a common treatment for cancer, aims to disrupt and destroy rapidly growing cancer cells. While it can be effective, it often faces challenges due to the dense nature of tumor tissue, which can hinder the penetration of drugs to the inner layers of cells. Additionally, chemo drugs can damage healthy cells, leading to unpleasant side effects.
In a recent study published in ACS Applied Nano Materials, a team led by former CU Boulder graduate student Shane Curry, explored a novel technique to tackle this issue. They combined high-frequency ultrasound waves with sound-responsive particles, aiming to reduce the protein content of tumors and make them more susceptible to treatment.
Andrew Goodwin, the senior author of the study and an associate professor at CU Boulder's Department of Chemical and Biological Engineering, believes that softening tumors in this way could significantly improve the effectiveness of chemotherapy.
"Tumors can be likened to a complex city with poorly laid out highways, making it difficult for drugs to navigate through. We want to explore ways to enhance these transport routes so that the drugs can reach their target and do their job effectively," Goodwin explained.
Ultrasound has been used in the past to treat cancer by breaking down tumor tissue, but like chemotherapy, it can also cause damage to healthy tissues. The researchers' innovative particles offer a potential solution by allowing for the treatment of tumors with less intense sound waves, making the procedure safer for patients.
"A major challenge in many tumor treatments is achieving therapeutic doses without harming healthy tissue. These particles could expand the applications and enhance the potency of various treatments," Curry emphasized.
The concept of using sound to manipulate body tissue is fascinating. Sound waves create physical vibrations that move through air, liquids, and solid objects. Goodwin describes the sounds we hear as small packets of fluctuating pressure moving through the space around us.
"When a pressure packet pushes against your eardrum, it vibrates, and these vibrations are interpreted by your brain," he explained.
Ultrasound imaging, commonly used during pregnancy, utilizes this principle to visualize the inside of the body. It sends sound waves into the body, and the echoes created as these waves bounce off internal organs and tissues are converted into live images and videos.
Doctors have also employed ultrasound to treat cancer, but the strong sound waves can damage healthy tissue and disrupt blood vessels, heightening the risk of cancer spreading to other parts of the body.
To address this issue, Goodwin and his team developed microscopic particles that vibrate and pulse in response to sound waves. High-frequency ultrasound waves cause these particles to vibrate rapidly, vaporizing the surrounding water and creating tiny bubbles through a process called cavitation.
These particles, measuring approximately 100 nanometers across, are made from silica and coated with a layer of fatty molecules.
In their study, the researchers added these particles to both 2D and 3D cultures of tumor tissue. When ultrasound was applied, the particles altered the structure of both types of cultures, but with different outcomes.
In the 2D cultures, consisting of a layer of cells grown on a plastic dish, the particles destroyed the tumor tissue. However, in the more lifelike 3D cultures, the particles reduced the amounts of specific proteins surrounding the tumor cells, making the tissue softer.
The fact that the cells in the 3D culture remained intact is encouraging, Goodwin said. It suggests that the treatment softened the tumor tissue without destroying it, reducing the likelihood of damage to healthy tissue.
Goodwin believes this treatment approach could be particularly effective for cancers with tumors located in specific parts of the body, such as prostate, bladder, ovarian, and breast cancer. Other cancers, like those affecting the blood and bones, may be more challenging to treat with this method due to their diffuse nature.
Currently, Goodwin and his team are testing similar sound-responsive particles to treat tumors in mice. Eventually, they hope to administer these particles inside the human body.
Goodwin envisions a future where these particles could be attached to antibodies, immune system proteins that bind to invaders like bacteria and viruses. These antibody-particle complexes could then be introduced into the bloodstream, allowing them to travel to the tumor site. Once the particles reach their destination, ultrasound could be applied to test the treatment's effectiveness.
While this vision may still be some time away, Goodwin is optimistic about the potential of this treatment.
"The technology for focused ultrasound has advanced significantly in the last decade. I'm excited about the possibility of our lab-built particles integrating with the acoustic, imaging, and therapy technologies used in clinical settings," he concluded.
This innovative approach to cancer treatment offers a promising avenue for further exploration and development, potentially bringing us one step closer to defeating this deadly disease.
