Oregon Health & Science University (OHSU) researchers have developed a groundbreaking nanoparticle technology that could revolutionize ultrasound-based cancer treatments, making them both more effective and safer for patients while reducing the risk of tumor recurrence.
The innovative approach, detailed in a recent study published in the journal Nano Letters, addresses key limitations of high-intensity focused ultrasound (HIFU) therapy, particularly in the area of mechanical tumor ablation—a technique that uses energy to destroy solid tumors without surgery.
Overcoming Critical Limitations in Ultrasound Cancer Treatment
Traditional focused ultrasound treatments face two significant challenges: they typically require high energy levels that can generate excessive heat and damage healthy surrounding tissues, and even when tumors are successfully broken up, surviving cancer cells can lead to recurrence.
"In this study, we developed a tiny particle—about a thousand times smaller than the width of a sheet of paper—that helps treat cancer more effectively," explained Michael Henderson, co-lead author of the study and a Ph.D. student in biomedical engineering at OHSU.
The engineered nanoparticles feature small bubbles on their surface that, when targeted with focused ultrasound, pop and release energy that destroys tumors with remarkable precision. Additionally, the particles are coated with a specialized peptide that enhances their ability to adhere to tumors and penetrate cancer cells.
A "One-Two Punch" Against Cancer
To further enhance therapeutic efficacy, the research team attached potent chemotherapy drugs to the peptide on the nanoparticle's surface, creating what co-lead author Li Xiang, Ph.D., describes as a "one-two punch" against cancer.
"The ultrasound physically destroys the tumor, and the drug helps eliminate any leftover cancer cells that might cause the tumor to return," said Xiang, a postdoctoral scholar with OHSU's Cancer Early Detection Advanced Research Center (CEDAR).
This dual-action approach demonstrated impressive results in preclinical models of human melanoma, achieving deeper tumor destruction and more effective drug delivery than either treatment modality alone.
Dramatic Reduction in Energy Requirements
One of the most significant advantages of the new technology is its ability to dramatically reduce the energy needed for effective ultrasound treatment.
"Our nanoparticles reduce the energy needed for ultrasound treatment by up to 100-fold," Henderson noted. "This allows us to use short ultrasound pulses to disrupt tumors mechanically, without overheating surrounding tissue."
Promising Preclinical Results
When tested in mice with human melanoma tumors, the combined treatment—ultrasound plus drug-loaded nanoparticles—produced significantly better outcomes than either approach used independently. In some cases, tumors completely disappeared, and overall survival improved beyond 60 days with no major side effects observed.
Adem Yildirim, Ph.D., the study's senior author and assistant professor of oncological sciences at OHSU, emphasized the evolution of this research: "What began in 2018 as research into nanoparticle-assisted tumor ablation has evolved into a multifunctional platform enabled by simple mixing—we're now excited to bring this into immunotherapy."
Broader Applications Beyond Cancer
While the current research focuses on cancer treatment, the technology platform has potential applications beyond oncology. The researchers suggest it could eventually be adapted for treating infections or cardiovascular disease, where combining mechanical intervention with drug therapy might prove beneficial.
Future Directions
The research team is now exploring how this technology might be integrated with immunotherapy approaches to create even more effective cancer treatments.
"While this work is still in the early stages, it lays the foundation for a new kind of nanoparticle-based therapy that could improve how we approach hard-to-treat tumors," Henderson said.
OHSU has been at the forefront of implementing high-intensity focused ultrasound technology in clinical settings, becoming the first hospital in Oregon to offer prostate cancer treatment using a robotic-assisted HIFU device. This latest research represents a significant step forward in expanding the capabilities and applications of ultrasound-based cancer therapies.
The development of these multifunctional nanoparticles could ultimately transform treatment options for cancer patients, particularly those with solid tumors that are difficult to treat with conventional methods, offering a less invasive alternative with reduced side effects and improved outcomes.
