Initial tests on mice showed that the drug safely reached its target and helped protect mice from glioblastoma tumors, which are highly aggressive and difficult to treat, giving hope for the development of safer and more effective future treatments.
Glioblastomas are among the most dangerous types of brain cancer because they are difficult to detect early and disrupt the body's natural immune response, making traditional treatments less effective. They are also difficult to access due to their location in the brain or along the delicate central nervous system, where they cause swelling and compression of surrounding tissues, depleting their blood supply.
Previously, researchers tried to alert the immune systems of mice to the presence of a hidden cancer by stimulating interferon genes in cancer cells (STING) - interferon genes usually alert the body to a viral infection - but the drugs broke down quickly, requiring multiple surgical interventions to reach the tumor directly.
To overcome this obstacle, neuroscientist Akanksha Mahajan and her colleagues developed a non-surgical method based on nanotechnology.
Mahajan says, "Our goal is to reduce patient suffering, and we thought of using spherical nucleic acid platforms to deliver drugs in a safe and non-invasive way."
The researchers transformed the molecules that activate the STING pathway into spherical genetic material and wrapped them around a core of gold nanoparticles to maintain their stability for a longer period. When tested on mice with glioblastoma tumors, this method successfully activated the STING pathway, which in turn inhibited tumor growth.
"This approach offers hope for finding safe and effective treatments for glioblastoma, and possibly other types of cancer resistant to immunotherapy," says neurosurgeon Alexander Stig of the University of Washington. "It is a crucial step toward clinical application."
He adds: "We have demonstrated that precisely engineered nanostructures, such as globular nucleic acids, are able to safely and effectively activate a strong immune response within the brain."
The researchers point out that the road to human clinical trials is still long, and that this approach needs to be supported by additional therapeutic methods, as cancer cells can sometimes bypass the STING pathway. However, when the nasal drops were combined with other immunomodulatory drugs, the researchers were able to stimulate a long-lasting immune response against glioblastomas in mice.
The study was published in the Proceedings of the National Academy of Sciences (PNAS).
