We’re still using a method from the 1940s to treat cancer.
The era of chemotherapy was one that first emerged over 80 years ago. And as of 2021, it’s still by far one of the top three most common forms of cancer therapy.
Although it’s effective in killing off cancer cells, the method also wipes out masses of healthy cells. Often, if the patient is healthy, these cells can be quickly replaced, but many of those with cancer have other health conditions, making this process more difficult and their bodies more susceptible to foreign infection. The immune system can undergo so much damage from chemotherapy that the recovery time is roughly 9 months after treatment is completely halted.
Carving out the tumor isn’t the best idea either.
Surgery is another common method of therapy. But often the cancerous lumps lodge themselves in areas of the body that are just to risky for physical man-handling that the patient is more likely to die from a potential surgery complication than from the cancer itself. And getting surgery will only remove the majority — the rest needs to be killed off by chemotherapy before the remaining continue to grow.
Nanotechnology is becoming increasingly apparent in cancer treatment and research.
Applying this emerging technology to open up untouched avenues of treatment gives humans a greater promise that those with incredibly difficult diseases like cancer can potentially go on into the future to live normal and fulfilling lives.
In a major advancement in nano medicine, Arizona State University (ASU) scientists, in collaboration with researchers from the National Center for Nanoscience and Technology (NCNST), of the Chinese Academy of Sciences, have successfully programmed nanobots to cut off the blood supply to tumors. This would essentially cut off their main source of fuel and leave them to die isolated from starvation. The tumors would shrink and the cancer’s ability to spread would be greatly reduced, being able to remove potentially all the cancer without needing surgery or risking damage to healthy cells via chemotherapy.
The initial goal was to specifically cut-off tumor blood supply by inducing blood coagulation with high therapeutic efficacy and safety profiles in multiple solid tumors using DNA-based nano-carriers. However, the system is now being designed to be a fully programmable robot; one that can navigate through the blood stream, find target blood vessels and create blockage entirely on its own.
Making the robot out of DNA origami.
Each nanorobot is made from a 2D, rectangular DNA origami sheet, 90 nanometers by 60 in dimension.
- An average of four thrombin molecules are attached (thrombin is an enzyme in blood which causes the clotting of blood)
- The flat sheet is curled into itself to made a hollow tube (like rolling up a poster board)
Twins with the Trojan horse.
However, the team had to ensure the nanobots have the capability to recognize cancer cells apart from normal ones, so then the effects of the thrombin wouldn’t touch and negatively affect proper functioning areas of the body. The key was to include a special payload on the cylinder’s surface, called a DNA aptamer. This aptamer would be specific to a target protein, which in this case is called nucleolin, a substance which is abundant on the surface of tumor cells, and absent on the surface of healthy ones.
Once the aptamer find its target and binds to the inner lining of the tumor blood vessel, the cylinder structure unrolls and exposes the unsuspecting potent drug, the thrombin, to quickly build a solid wall and clot the blood vessel.
And it’s not just one nanobot tirelessly working; in fact, thousands of them are injected, which soon congregated in large numbers in the blood stream to pinpoint and home in on the tumors just hours after it initially enters the circulatory system.
Great promises from a safe and sound design.
The nanotechnology was tested on mice with melanoma cancer, by using an IV to inject the bots into their blood stream. Through observation, they quickly surrounded themselves around the tumors and killed them off within 24 hours, without any effect on nearby healthy tissue. Ultimately, the life expectancy in treated mice was 45 days, compared to 20.5 days in non-treated mice.
Most importantly, there was no evidence of the nanobots seeping into the brain where it could cause dangerous side effects, such as a stroke. And after their attacks, the nanorobots were collectively cleared and degraded from the body after 24 hours via natural processes.
Physically small, but the science will come a long way.
Moreover, these nanobots can be used to treat virtually all types of cancer, since all solid tumour-feeding blood vessels are essentially the same. Over 5.5% of the world’s population is suffering from this illness, so this innovation is guaranteed to impact the lives of people by the millions.
With their successes, the researchers are now actively pursuing clinical partners to further develop this technology, moving beyond mice and hopefully getting this technology to the market within the next decade. It’s clear the century old form of cancer treatment is one which is becoming more and more obsolete, with better and improved methods emerging in society.
“I think we are much closer to real, practical medical applications of the technology. Combinations of different rationally designed nanorobots carrying various agents may help to accomplish the ultimate goal of cancer research: the eradication of solid tumours and vascularized metastases.”
— Professor Hao Yan, Director of the Arizona State University Biodesign Institute’s Centre for Molecular Design and Biomimetics
- Ashley
