Scientists have successfully developed nano-robots using DNA origami that can shrink tumors by cutting off their blood supply, paving the way for novel cancer therapies.
Each nano-robot is made from a flat, rectangular DNA origami sheet, 90 nanometres by 60 nanometres in size.
A key blood-clotting enzyme, called thrombin, is attached to the surface.
Thrombin can block tumor blood flow by clotting the blood within the vessels that feed tumor growth, causing a sort of tumor mini-heart attack, and leading to tumor tissue death, researchers said.
“We have developed the first fully autonomous, DNA robotic system for a very precise drug design and targeted cancer therapy,” said Hao Yan, from Arizona State University (ASU) in the US.
“Moreover, this technology is a strategy that can be used for many types of cancer, since all solid tumor-feeding blood vessels are essentially the same,” said Yan.
DNA origami, in the past two decades, has developed atomic-scale manufacturing to build more and more complex structures.
The bricks to build their structures come from DNA, which can self-fold into all sorts of shapes and sizes – all at a scale one thousand times smaller than the width of a human hair – in the hopes of one day revolutionizing computing, electronics and medicine.
Until now, the challenge to advancing nano-medicine has been difficult because scientists wanted to design, build and carefully control nano-robots to actively seek and destroy cancerous tumors – while not harming any healthy cells.
Researchers including those from Chinese Academy of Sciences overcame this problem by using a simple strategy to very selectively seek and starve out a tumor.
“These nano-robots can be programmed to transport molecular payloads and cause on-site tumor blood supply blockages, which can lead to tissue death and shrink the tumor,” said Baoquan Ding, a professor at National Center for Nano-science and Technology (NCNST) in China.
To perform the study, scientists used a mouse tumor model, where human cancer cells are injected into a mouse to induce aggressive tumor growth. Once the tumor was growing, the nano-robots were deployed to come to the rescue.
The nano-robot is programmed to only attack cancer cells, researchers said. Once bound to the tumor blood vessel surface, the nano-robot delivers its unsuspecting drug cargo in the very heart of the tumor, exposing an enzyme called thrombin that is key to blood clotting.
The nano-robots worked fast, congregating in large numbers to quickly surround the tumor just hours after injection.