Among malignant brain tumors, astrocytoma is particularly common and equally dangerous: Surgical removal of this aggressively growing tumor can be difficult because the cells invade the healthy surrounding tissue. Moreover, in seven out of ten cases, the cancer returns after treatment, and the prognosis is correspondingly poor. The five-year survival rate is only about five percent. Now, a team from Empa and the hospital network HOCH Health Ostschweiz in St. Gallen led by neurosurgeon Isabel Hostettler wants to improve the chances of curing this type of tumor with a novel and gentler therapeutic approach based on so-called nanozymes. The project is being carried out thanks to the generous support by the Hedy Glor-Meyer Foundation, the Swiss Cancer Foundation, and four other foundations.

Bypassing the blood-brain barrier

Currently, surgery, radiation, and chemotherapy are combined to treat astrocytomas. However, the location of the tumor – the brain – poses a problem, particularly for drug therapy. This is because the body's own protective mechanism, the blood-brain barrier, which protects the organ from harmful influences from the bloodstream, also prevents certain therapeutics from gaining access to the brain.
Empa researcher Giacomo Reina and his team from the Nanomaterials in Health laboratory in St. Gallen now want to circumvent this barrier with a clever approach: They are developing biocompatible nanomaterials acting as nanomedicine that can be used directly on-site during brain tumor surgery. “Since cancer cells have a particularly active metabolism, the drugs specifically accumulate in the tumor tissue,” says Reina. Another advantage is that the nanozymes can be activated with near-infrared light for a particularly precise, controllable effect.

Gentle but powerful

This novel therapy combines several mechanisms of action: Nanozymes, nanomaterials with enzyme-like activity, can, for instance, activate inactive precursors of drugs or generate reactive oxygen compounds that damage tumor cells. Their tiny size allows them to penetrate deep into the tissue and attack malignant cells several millimeters away. In addition, thanks to the ability to be activated by IR light, the dosage and thus the side effects of the therapy can be kept to a minimum.
The team is now ready to tackle its ambitious goals. At the end of the four-year project, the nanomedicine should be ready for clinical testing as a minimally invasive and low-impact ass-on to existing therapies. The researchers have high hopes: “Nanozymes could possibly even prevent relapses in astrocytoma if the cancer has already become resistant to conventional chemotherapy,” says Giacomo Reina. What's more, the approach also has promising potential for the treatment of other brain and spinal cord tumors.

Empa research initiative "Oncology"

With around 45,000 new cases and 17,000 deaths each year, cancer remains one of the greatest challenges to public health in Switzerland. Empa's oncology initiative aims to tackle this problem with innovative, material-based approaches that take into account the genetic and metabolic fingerprint of patients. Five Empa laboratories are pooling their expertise in (nano)materials science, sensor technology, imaging, and advanced in vitro and in silico models to develop new strategies for diagnosis, monitoring, and therapy. The aim is to put these innovative approaches into practice in collaboration with partners from clinics and industry. The first phase of the initiative will run from 2025 to 2035. Another example of projects within the oncology initiative is the investigation of thyroid carcinomas using an innovative 3D imaging technique. This technology enables a significantly more precise and, above all, non-destructive analysis of biopsy samples.