Composed of iron oxide and enhanced with cobalt (a process called doping to change the material's properties), these nanoparticles exhibit exceptional heating efficiency under the influence of an alternating magnetic field.
When these particles accumulate in cancerous tissue after being injected intravenously, they can quickly raise temperatures that weaken or destroy cancer cells.
The mouse model study, published in Advanced Functional Materials, is part of ongoing nanomedicine research by OSU College of Pharmacy scientists.
Nanoparticles are substances as small as one billionth of a meter that have special properties due to their small size and high surface area to volume ratio.
Magnetic nanoparticles have shown anti-cancer potential for years, scientists say, but currently magnetic hyperthermia can typically only be used in patients whose tumors can be accessed via a hypodermic needle - that is, if the particles can be injected directly into the cancer.
"Currently, the therapeutic temperatures required for magnetic nanoparticles (above 44 degrees Celsius) can only be achieved through direct injection," said Professor of Pharmacy Oleh Taratula. "And the heating efficiency of these nanoparticles is only moderate, which means you need to maintain a higher concentration of nanoparticles in the tumor (higher than what is typically achieved with systemic administration) to generate enough heat."
Taratula and colleagues at Oregon State University, Oregon Health and Science University, and Indian Institute of Technology Mandi used a novel thermal decomposition method, which they called a two-step process of seeding and growing, to create cobalt-doped iron oxide nanoparticles in the shape of a cubic bipyramid. Their paper is the first report of such nanoparticles with a specific shape.
"These nanoparticles exhibit an astonishing ability to heat up quickly, reaching 3.73 degrees Celsius per second under an alternating magnetic field," said Prem Singh, a postdoctoral researcher at the School of Pharmacy. "This is twice the heating performance of our previously published cobalt-doped iron oxide nanoparticles."
This means that patients with ovarian cancer can receive an intravenous injection and have their tumors stop growing after a 30-minute non-invasive magnetic field treatment. The researchers noted that brief treatments can improve patient comfort and compliance.
Cancer-targeting peptides help nanoparticles accumulate in tumors, and because the heating efficiency of the particles is so high, the necessary concentration of nanoparticles can be achieved without high doses, limiting toxicity and side effects.
Olena Taratula, associate professor of pharmacy at Oregon State University, said: "This is the first time that systemically injected nanoparticles have been shown to heat tumors to more than 50°C, significantly exceeding the therapeutic threshold of 44°C for effective treatment at clinically relevant doses. Now, magnetic hyperthermia has a very broad range of applications and can be extended to a variety of hard-to-reach tumors, making treatment more flexible and broad."
Compiled from /ScitechDaily