Nanorobots detonate hidden weapon to kill cancer

In what can be termed as a promising avenue in cancer treatment, researchers have developed nanorobots that have demonstrated the ability to kill cancer cells in mice.

Previously, Karolinska Institutet researchers developed structures that organize death receptors on the surface of cells, thereby inducing cell death. These structures are composed of six peptides (chains of amino acids) arranged in a hexagonal pattern.

Death receptors are like switches on the surface of cells that, when activated by specific signals like tumor necrosis factor (TNF), trigger a process leading to cell self-destruction, called apoptosis. They help control cell survival and death in living things.

The hexagonal nano-pattern of the peptides acts as a deadly weapon. Administering it as a drug would indiscriminately kill cells throughout the body, posing a significant risk. The team says that to solve this problem, the weapon must be hidden in a DNA nanostructure.

DNA Origami Emergency Stop Switch

The research team applied DNA origami, a technique for creating nanoscale structures from DNA. This process allows the team to design very small shapes with great precision.

According to the researchers, this technology allows them to place DNA fragments exactly where we want them and associate proteins with them to create precise patterns and structures at the molecular level. They have since applied this technology to develop a “kill switch” that, once triggered, acts as intended.

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

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

In test-tube cell analyses, the researchers demonstrated that the peptide weapon remains hidden in the nanostructure at a normal pH of 7.4. However, when the pH drops to 6.5, the weapon is exposed and exhibits a significant cell killing effect.

Targeted cancer treatment

The effectiveness of the nanorobot was tested by introducing it to animals suffering from tumors linked to breast cancer. Compared to mice given an inactive version of the nanorobot, this resulted in a 70% decrease in tumor growth.

“We now need to test 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 method's potential side effects before it can be tested on humans.

Additionally, the researchers plan to explore the possibility of improving the nanorobot's targeting capabilities by attaching proteins or peptides to its surface that bind specifically to certain types of cancer.

Details of the team's research were published in the journal Nature Nanotechnology.