Developing nanorobots that kill cancer cells with a "hidden weapon"

Scientists have developed nanorobots that have been shown to kill cancer cells in mice, in what could be a promising way to treat cancer.

Scientists at the Karolinska Institute in Sweden have developed robots that contain a weapon hidden in a nanostructure and only appear in the microenvironment of the tumor, while sparing healthy cells.

This research group at Karolinska Institutet has previously developed structures that can regulate so-called death receptors on the surface of cells, leading to cell death.

These structures consist of six peptides (chains of amino acids) arranged in a hexagonal pattern.

Death receptors are like switches on the surfaces of cells that, when triggered by specific signals such as tumor necrosis factor (TNF) — a protein capable of attacking and destroying tumor cells — initiate a process that leads to the cell’s self-destruction, known as apoptosis. It helps control cell survival and death in living organisms.

The hexagonal nano-peptide pattern acts as a deadly weapon. Administering it as a drug would kill cells indiscriminately throughout the body, posing a significant risk. To solve this problem, the team claims, the weapon must be hidden inside a DNA nanostructure.

The research team was practicing DNA origami, a technique for creating nanostructures from DNA. The process allows the team to design very small shapes with high precision.

According to the scientists, the technique allows them to place pieces of DNA exactly where they want them and link proteins to create precise patterns and structures at the molecular level.

Since then, they have applied this technology to develop a “kill switch” that works as intended when triggered.

“We were able to disguise the weapon in such a way that it can only be detected in the environment inside and around the solid tumor,” Björn Högberg, a professor at the Department of Medical Biochemistry and Biophysics at Karolinska Institutet, said in a statement. “This means that we have created a kind of nanorobot that can specifically target and kill cancer cells.”

The nanorobot weapon is activated by the acidic, low-pH microenvironment that typically surrounds cancer cells.

During laboratory analyses, the scientists demonstrated that the peptide weapon remains hidden within the nanostructure at a normal pH of 7.4. However, when the pH drops to 6.5, the weapon becomes exposed and shows a significant cell-killing effect.

targeted cancer therapy

The nanorobot was tested for its effectiveness by introducing it into animals with breast cancer-associated tumors. Compared to mice that received an inactive version of the nanorobot, this resulted in a 70% reduction in tumor growth.

“We now need to verify whether this works in more advanced cancer models that more closely resemble the real human disease,” said Yang Wang, a researcher at the Department of Medical Biochemistry and Biophysics at Karolinska Institutet.

The team now needs to determine the potential side effects of this method before testing it in humans. In addition, the team plans to explore the possibility of enhancing the targeting capabilities of the nanorobot by attaching proteins or peptides to its surface that are specifically associated with certain types of cancer.

The research paper was published in detail in the journal Nature Nanotechnology.