An unusual method of fighting aggressive brain cancer has been found

US scientists have proposed a new method for delivering anti-tumor drugs against glioblastoma - one of the most aggressive types of brain cancer. The method is based on nasal administration of special nanostructures capable of activating an immune response in the tumor.

As reported by BAKU.WS, the work is published in PNAS (Proceedings of the National Academy of Sciences).

Glioblastoma often responds poorly to therapy, in part due to the so-called "cold" immune environment: the presence of the tumor barely activates the body's natural defenses. The immune system can be strengthened by activating a special intracellular pathway called STING. However, drugs that affect it break down quickly and require direct injection into the tumor, making treatment extremely difficult and invasive.

To simplify this therapy method, scientists created a new type of spherical nucleic acids - nanoparticles with a core and short DNA fragments on the surface that trigger the STING signaling pathway. To evaluate how such structures move in the body, scientists incorporated a marker visible in the near-infrared range. This allowed tracking the movement of the drug after dripping it into the nasal passages of mice with glioblastoma.

The nanostructures passed through the olfactory pathways directly to the brain, bypassing the systemic bloodstream. The main immune response formed in the tumor and nearby immune cells, while the drug barely penetrated other organs, reducing the risk of side effects.

"The nanoparticles successfully activated the STING signaling pathway, which enhanced the immune response against the tumor. In combination with agents that stimulate T-lymphocytes, the new technology eliminated tumors in mice after one or two doses and formed long-term protection against recurrence," the scientists explained.

However, the researchers note that STING activation is not sufficient for full treatment of glioblastoma: tumors use several mechanisms to suppress immunity. Currently, the team is developing combined nanostructures capable of triggering multiple immune pathways within a single course of therapy.