Researchers at Oregon State University have developed and tested in a mouse model a new type of nanoparticle that enables the removal of melanoma tumors with a low-power laser.
After the systemically administered nanoparticles accumulate in cancerous tissue, exposure to near-infrared light causes them to heat up and destroy the melanoma cells, leaving healthy tissue unharmed.
The study led by Olena Taratula and Prem Singh of the Oregon State University College of Pharmacy represents a huge step toward solving a persistent problem with using photothermal therapy to treat melanoma, the deadliest form of skin cancer: Conventional nanoparticles require lasers with power densities that are unsafe for the skin.
Findings were published in Advanced Functional Materials.
Taratula, associate professor of pharmaceutical sciences, and Singh, a postdoctoral researcher in Taratula's lab, based their new theranostic platform - it can be used for both treatment and diagnosis - on gold nanorods. The nanorods are coated with an iron-cobalt shell and tightly loaded with a dye that heats up upon exposure to near-infrared light - invisible, low-frequency radiation able to penetrate deeply into human tissue.
A key feature of the platform is its use of resonance energy transfer, a nanoscale process in which energy moves directly from one molecule to another. The highly efficient nature of resonance energy transfer is what allows the nanoparticles to heat up quickly under laser exposure far below the safety threshold for maintaining healthy skin.
"The safety limit is 0.33 watts per centimeter squared," Taratula said. "When we used 0.25 watts per centimeter squared with our nanoparticles, a single treatment of an aggressive melanoma mouse model, developed in the lab of our OSU colleague Adam Alani, completely ablated the tumor."
According to the American Cancer Society, skin cancer is by far the most common type of cancer in the United States, and melanoma is the most dangerous type. Melanoma, which starts in the skin's pigment-producing cells and is typically caused by exposure to ultraviolet light, accounts for only about 1% of skin cancers but is responsible for the majority of skin cancer deaths.
More than 8,000 people in the U.S. died of melanoma in 2025, according to the National Institutes of Health, and more than 100,000 new cases were diagnosed.
"Many of those cases likely were treated with a surgical procedure that required a big incision and a significant amount of tissue removal to help ensure no cancerous cells were left behind," Singh said. "Photothermal therapy on the other hand is a minimally invasive treatment, and our work establishes resonance energy transfer as a truly transformative strategy for coming up with next-generation photothermal therapy agents."
The design of the nanoparticle presented in this research, he added, allows it to also act as an imaging agent that enables fluorescence-guided ablation therapy - an imaging system shows where to focus the laser during tumor removal.
The OSU College of Pharmacy, the OSU Advantage program, the National Cancer Institute of the National Institutes of Health and the Eunice Kennedy Shriver National Institute of Child Health and Human Development supported this research.
The collaboration included Oregon State's Constanze Raitmayr, Syed Zaki Husain Rizvi, Ammar Salem, Vladislav Grigoriev, Tetiana Korzun, Karthickraja Duraisamy, Akshay Vyawahare, Kongbrailatpam Shitaljit Sharma, Ana Paula Mesquita Souza, Yoon Tae Goo, Manali Phawde, Chrissa Kioussi and Oleh Taratula, and Yitayal Admassu Workie of Addis Ababa Science and Technology University.
