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Scientists develop DNA nanorobots capable of stopping cancer growth

15 February 2018

These DNA nanorobots do so by seeking out and injecting cancerous tumors with drugs that can cut off their blood supply, shriveling them up and killing them. Staining studies also highlighted thickening of alveolar wall and fibrosis, "suggesting a consequential remodeling of the tumor tissues into normal lung tissues", the authors claim.

The team took a rectangular piece of DNA origami sheet - measuring just 90 nanometers by 60 nanometers - and peppered it with a protein known as thrombin.

The DNA origami sheet, with its associated clotting agent, is then folded up into a ring-like structure.

"This ability can be harnessed to kill tumour cells by developing a system where the thrombin only causes clots in the blood vessels that are feeding the tumour, and not elsewhere in the body". The next step is to investigate any damage-such as undetected clots or immune-system responses-in the host organism, he says, as well as to determine how much thrombin is actually delivered at the tumor sites. After binding to the blood vessel surface, they would release the thrombin into the tumor. Yan's team also found that nanorobot treatment increased survival and led to smaller tumors in a mouse model of melanoma, and in mice with xenografts of human ovarian cancer cells. From treating tumors to delivering medicine to specific areas in the body, the future would look brighter with nanorobots in it. The nanorobot therapy was particularly effective in a melanoma mouse model, in which three of eight treated mice showed complete tumor regression and more than double median survival time. But perhaps the most significant part of the tech is its precision, at least in the mouse models: The programmed DNA bots avoided causing any clotting or harm to healthy cells. The researchers also demonstrated this in the healthy tissue of Bama miniature pigs, adding weight to the finding that the nanorobot is, as they describe it, "safe and immunologically inert". Once coagulation occurs and blood flow has been cut off to the tumor, it shrinks.

Most importantly, there was no evidence of the nanorobots spreading into the brain where they could cause unwanted side effects, such as a stroke.

In the Arizona State University (ASU) study, scientists injected human cancer cells into a mouse to induce aggressive tumor growth. "The thrombin delivery DNA nanorobot constitutes a major advance in the application of DNA nanotechnology for cancer therapy", Yan said. They are now looking for partners to develop the technology for clinical applications. "Furthermore, the current strategy may be developed as a drug delivery platform for the treatment of other diseases by modification of the geometry of the nanostructures, the targeting groups, and the loaded cargoes".

Scientists develop DNA nanorobots capable of stopping cancer growth