In a groundbreaking development in cancer treatment, researchers have created nanobots that have shown the ability to kill cancer cells in mice. This innovative approach offers hope for more targeted and effective cancer therapies in the future.

Researchers at Karolinska Institutet previously developed structures that organize death receptors on the surface of cells, inducing cell death. These structures consist of six peptides (amino acid chains) arranged in a hexagonal pattern. Death receptors are like switches on cell surfaces that, when activated by signals such as tumor necrosis factor (TNF), initiate apoptosis, or programmed cell death. This process helps control cell survival and death in living organisms.

The hexagonal nanopattern of peptides acts as a lethal weapon. However, administering it directly as a drug would indiscriminately kill cells throughout the body, posing significant risks. To address this issue, the team encapsulated the weapon within a DNA nanostructure.

The research team has been utilizing DNA origami, a technique for creating nanoscale structures out of DNA. This process allows for precise design and placement of DNA pieces, enabling the attachment of proteins to form accurate molecular patterns and structures.

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

The nanorobot’s weapon is activated by the acidic microenvironment, characterized by a low pH, typically surrounding cancer cells. In test tube analyses, researchers demonstrated that the peptide weapon remains concealed within 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.

The efficacy of the nanorobot was tested in animals with breast cancer tumors. Compared to mice that received an inactive version of the nanorobot, those treated with the active nanorobot experienced a 70 percent reduction in tumor growth.

“We now need to investigate 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, Karolinska Institutet.

Before this treatment can be tested on humans, the team needs to determine its potential side effects, such as the risk of killing healthy cells if the conditions for activation are met outside of tumors.

“These results are an early proof of concept and are in no way a real treatment today. Our plan to investigate this includes moving to more realistic animal models that incorporate, for example, mice with humanized death receptors,” Högberg told Interesting Engineering.

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

This pioneering work represents a significant step towards more precise and effective cancer treatments, potentially revolutionizing the way we approach this devastating disease.

By Impact Lab