Mechanical Nanosurgery Uses Nanotechnology and Precision Magnetics to Destroy Therapy-Resistant Brain Cancers

Although various treatments, such as surgery, radiotherapy, and chemotherapy, are available, patients' median survival time is only about 15 months. The global standard-of-care for GBM patients currently involves chemotherapy with a drug called temozolomide (TMZ), which prolongs life expectancy by approximately two months compared to radiotherapy alone. However, GBM cells can become resistant to TMZ, diminishing its effectiveness and increasing the chances of tumor recurrence. In response, researchers are exploring an innovative method called mechanical nanosurgery, which uses precision magnetics to target cancer cells within the tumor.

Scientists at The Hospital for Sick Children (SickKids, Toronto, ON, Canada) and the University of Toronto (U of T, Toronto, ON, Canada) are collaborating to develop mechanical nanosurgery as a potential treatment for tumor cells, including those resistant to chemotherapy. Magnetic carbon nanotubes (mCNTs) are a type of nanomaterial—microscopic, cylindrical tubes made of carbon and filled with iron—that become magnetized when exposed to an external magnetic field.

In their study, the researchers coated mCNTs with an antibody that identifies a specific protein associated with GBM tumor cells. When injected into the tumor, the antibodies on the mCNTs guide them to the tumor cells, which then absorb them. The team's ongoing research suggests that mechanical nanosurgery could have additional applications in treating other cancer types. The study's mouse model demonstrated that the mechanical nanosurgery technique universally reduced GBM tumor size, including in cases of TMZ-resistant GBM.

“Once the nanotubes are inside the tumor cell, we use a rotating magnetic field to mechanically mobilize the nanotubes to provide mechanical stimulation,” said Dr. Yu Sun, Professor of Mechanical Engineering and Director of the Robotics Institute at U of T. “The force exerted by the nanotubes damages cellular structures and cause tumor cell death.”

“Through the use of nanotechnology deep inside cancer cells, mechanical nanosurgery is a ‘Trojan Horse’ approach that could allow us to destroy tumor cells from within,” said Dr. Xi Huang, a Senior Scientist in the Developmental & Stem Cell Biology program at SickKids, whose previous research demonstrating that brain tumor cells are mechanosensitive helped to inform the approach. “Theoretically, by changing the antibody coating and redirecting nanotubes to the desired tumor site, we could potentially have a means to precisely destroy tumor cells in other cancers.”

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