The research team from the Karolinska Institute in Sweden has developed a DNA nano-robotic device that carries a "weapon" which only activates in the tumor microenvironment. After mouse experiments, the tumor growth was effectively reduced by 70%.
Let's take a trip back to 1966, to the science fiction movie "Fantastic Voyage," where a Soviet scientist escapes to the United States, on the brink of death due to spy-induced damage to his blood vessels. Five American doctors shrink to a fraction of a millionth of their size, turning into "ants," and enter the human body in a miniature submarine to perform vascular surgery. Fifty-eight years later, science fiction has become reality, and cancer treatment is facing a new direction.
The core breakthrough of this research is the creation of a "lethal switch." The KI research group had previously developed a structure that could organize so-called "death receptors" on the cell surface, leading to cell death. These structures are presented as six peptides assembled in a hexagonal pattern. The head of the nano-robot contains a cavity, in which there are exactly six cytotoxic ligands arranged in a hexagonal pattern.
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The art of constructing nano-scale structures using DNA as building materials is known as DNA origami, which has been a research topic of Högberg's research team for many years. The DNA origami technology can precisely control the spatial arrangement of ligands, ensuring optimal aggregation of death receptors, which is crucial for inducing effective cell death.
So, how is the "lethal switch" activated? The key lies in the low pH or acidic microenvironment that usually exists around cancer cells. Cell analyses conducted in test tubes showed that under normal physiological conditions, the peptide weapon (toxic ligand) remains hidden within the nano-robot inactive, maintaining a dormant and harmless state. However, when the pH drops to 6.5 (a typical pH value in cancer tissue), the "lethal switch" is triggered, and the DNA structure unfolds, exposing the cytotoxic ligands.
The research team conducted experiments on mice carrying human breast cancer xenograft tumors to test the therapeutic effect of the nano-robot. Compared to mice injected with inactive nano-robots, the tumor growth in the mice injected with the nano-device was effectively reduced by 70%.
This breakthrough also marks the continuous vigorous development of nanotechnology in the future, which may lead us to achieve the future envisioned by Ray Kurzweil, where extending human lifespan to 1000 years may no longer be a dream.
Article Address: https://www.nature.com/articles/s41565-024-01676-4