Nanotechnology in Healthcare: Getting Smaller and Smarter
November 3, 2016
We are living at the dawn of the nanomedicine age. I believe that nanoparticles and nanodevices will soon operate as precise drug delivery systems, cancer treatment tools or tiny surgeons. Let me introduce you the brave, new world of nanotechnology in healthcare.
Nanorobots having nanobreakfast with your red and white blood cells
When I was a kid, one of my favorite TV series was a French animation, Il était un fois… la vie (1986). I found it fascinating how the creators imagined the human body as a construction where tiny cars floated through the human veins, grab-cranes worked on teeth and bacteria as tiny monsters tried to attack innocent screaming lady-cells, while white blood cells defended the body as well-trained soldiers. Somehow similarly, the 1966 movie, Fantastic Voyage explored shrinking a medical team to microscopic size in order to save a renowned scientist’s life. The Argonauts travel through the bloodstream into the brain where the crew uses a laser gun to blast away a blood clot.
Now, imagine that all this could happen in real life… How about a nanometer sized cage that lets out insulin but doesn’t get attacked by our immune system? How about a nanorobot delivering dopamine directly to the brainstem for treating Parkinson’s disease? And how about injecting chemotherapy into cancer cells while keeping healthy cells untouched? Could you imagine microscopic robots inside you sending alerts to your smartphone that a disease is about to develop in your body? In such a scenario, the word symptom would be completely eradicated from our medical dictionaries.
Sounds like an idea out of science-fiction novel?
If you think that nanorobots and engineered nanoparticles are only part of the world created by Jules Verne or by Greg Egan in his novel, Diaspora, you might not heard about the winners of the 2016 Nobel Prize in chemistry. It was awarded to brilliant scientists Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard L. Feringa, very simply for having developed molecules with controllable movements. As Gizmodo acknowledges, although molecular nanotechnology is still in its infancy, by awarding the Nobel Prize to these three scientists, the Royal Swedish Academy of Sciences is acknowledging nanotechnology’s huge potential.
So, how did nanotechnology arrive at its current state and how will it change the notion of healthcare in the future?
“Nano” means smaller than micro-sculptures on pin-point
Nanotechnology is hardly comprehensible by the average human mind, because it is in a completely different dimension. Somewhere at the molecular and atomic level. Do you remember the micro-sculptures in the eye of a needle? Compared to the nanometer, the basic unit of measurement in nanotechnology, these are still huge. A nanometer is a million times smaller than the length of an ant. A sheet of paper is about 100, 000 nanometers thick. The ratio of the Earth to a child’s marble is roughly the ratio of a meter to a nanometer.
Essentially, nanotechnology comprises science, engineering and technology conducted at the nanoscale, which is about 1 to 100 nanometers. It is basically manipulating and controlling materials at the atomic and molecular level. Amazing, right?
The Story of Nanotechnology – From tiny “demons” to nanorobots in bloodstreams
As part of an 1871 thought experiment Scottish physicist James Clerk Maxwell imagined tiny “demons” that could redirect atoms one at a time. However, it was a long way to go from there until the birth of nanotechnology. The term molecular engineering was actually coined by MIT professor Arthur Robert von Hippel in the 1950s. On the evening of December 29, 1959, the famous physicist Richard Feynman described in his after–dinner lecture at the annual meeting of the American Physical Society how the entire Encyclopaedia Britannica could be written on the head of a pin, and how all the world’s books could fit in a pamphlet.
Continuing the thought experiment, Kim Eric Drexler, an MIT undergraduate in the mid–1970s, envisioned that molecule–sized machines could manufacture almost anything. In his book, Drexler described nanotechnology’s future role in revolutionizing other areas of science and technology that would lead to breakthroughs in medicine, artificial intelligence, and astronomy. His idea of an “assembler” could “place atoms in almost any reasonable arrangement,” thus allowing us to build almost anything that the laws of nature will allow.
Later, in 1991 carbon nanotubes were discovered, which are about 100 times stronger than steel only one–sixth their weight, and have unusual heat and conductivity characteristics. The Juno spacecraft currently on its way to Jupiter uses carbon nanostructure composite to provide electrical grounding, discharge static, and reduce weight. From the beginning it was inevitable that this technology would be used in medicine. Now, we are about to reach this point.
All kinds of nano under the microscope
Nanotechnology has two basic strands. The first one is the Drexlerian molecule-sized machine, which is able to build and manipulate its environment at the atomic level. The second one is “biological” nanotech, which basically uses DNA and the machinery of life to create unique structures made of proteins or DNA (as a building material).
1) DNA-based origami robots
One of the most forward–thinking experiments proved that DNA–based nanorobots can be inserted into a living cockroach and later perform logical operations upon command such as releasing a molecule stored within it. Such nanorobots are also called origami robots since they can unfold and deliver drugs, could eventually be able to carry out complex programs including diagnoses or treatments. One of the most astonishing feats is the accuracy of delivery and control of these nanobots, which are equivalent to a computer system. The other one is that the same basic design principles that apply to typical full-size machine parts can also be applied to DNA.
2) Scallop-like microbots and nanoswimmers
Researchers from the Max Planck Institute have been experimenting with exceptionally micro-sized – smaller than a millimeter – robots that literally swim through your bodily fluids and could be used to deliver drugs or other medical relief in a highly-targeted way. These scallop-like microbots are designed to swim through non-Newtonian fluids, like your bloodstream, around your lymphatic system, or across the slippery goo on the surface of your eyeballs.
ETH Zurich and Technion researchers have developed an elastic “nanoswimmer” polypyrrole (Ppy) nanowire about 15 micrometers (millionths of a meter) long and 200 nanometers thick that can move through biological fluid environments at almost 15 micrometers per second. The nanoswimmers might be programmed to deliver drugs and magnetically controlled to swim through the bloodstream to target cancer cells, for example.
3) Ant-like nanoengines
Ant–like robots are controlled magnetically, are very fast, can locate, and use tools. Moving through even flexible surfaces they can construct three–dimensional structures at an amazing pace. They could revolutionize both biotechnology and electronics manufacturing.
University of Cambridge researchers have developed the world’s tiniest engine, made of gold nanoparticles bound together with temperature-responsive gel polymers, capable of a force per unit-weight nearly 100 times higher than any motor or muscle. Researchers named the nanomachine ANT, since as real ants, they produce large forces for their weight.
4) Sperm-inspired microrobots
A team of researchers at the University of Twente (Netherlands) and German University in Cairo has developed sperm-inspired microrobots called MagnetoSperm that can be controlled by weak oscillating magnetic fields. When the 322 micron-long robot is subjected to an oscillating field of less than five millitesla — about the strength of your touristy fridge magnet from Manhattan — it experiences a magnetic torque on its head, which causes its flagellum to oscillate and propel it forward.
MagnetoSperm can be used to manipulate and assemble objects at nanoscales using an external source of magnetic field to control its motion. In the future, researchers hope to further scale down the size of the microrobot. The team is currently working on a method to generate a magnetic nanofiber that can be used as a flagellum.
5) Bacteria-powered robots
Drexel University engineers have developed a method for using electric fields to help microscopic bacteria-powered robots detect obstacles in their environment and navigate around them. It means that robots navigate with the help of electric fields, and they can be programmed into getting to a certain point or changing its route or avoid/go through objects.
Bacteria-powered robots might bring amazing changes in healthcare, which include delivering medication exactly to the point where it is needed, manipulating stem cells to direct their growth, or building a microstructure, for example.
6) Clottocyte nanorobots
I know the word “clottocyte” sounds strange, it means artificial mechanical platelet. These nanorobots function similarly to platelets that stick together to form a blood clot that stops bleeding. They could store fibers until they encounter a wound, and then disperse them to create a clot in a fraction of the time that platelets do. Blood–related microbivore nanorobots act like white blood cells, and could be designed to be faster and more efficient at destroying bacteria or similar invasive agents.
Thus, bacterial or viral infections could be eliminated from someone in a matter of minutes as opposed to the days required for antibiotics to take effect. Nanobots would also not have their potential side effects. So instead of taking medicine or having an injection after having got the flue, you just go to the pharmacy, ask for a non-prescription clottocyte nanorobot, and the flue is gone by the time you are out of the door.
7) Respirocyte nanorobots
These tiny little creatures act like red blood cells, but they would have the potential to carry much more oxygen than natural red blood cells do for patients suffering from anemia (when the body does not have enough healthy red blood cells). They might also contain sensors to measure the concentration of oxygen in the bloodstream. One day blood may become both a repository and symbiosis of nanorobots and our human cells.
How can we use the army of nanorobots?
The real advantage of having robots on the nanometer scale is having them work in large groups. One miniscule robot cannot make much of a difference. But a million of them might move the Golden Gate Bridge.
1) The most accurate drug delivery systems
The greatest potential in nanodevices lies in their ability to deliver drugs to the exact location where they are needed. There are many diseases – including cancer – where treatment causes lots of serious side-effects exactly because the active substance in the medication cannot differentiate between healthy and diseased tissues. In the future, nanotechnology could provide a great solution.
Imagine vaccine delivery with microneedle patches instead of taking drugs or having to suffer through injections! Microneedle patches could provide cheaper, simpler, and safer methods of delivery compared to traditional administration that requires skilled professionals and runs the risk of infection. Microneedles at micron–scale are coated with a dry formulation of vaccine that dissolves in the skin within minutes after applying the patch. Scientists proved that measles vaccine can be stabilized on microneedles and is comparably effective to the standard subcutaneous injection.
Imagine programmable nanoparticles, which might help tackle the day-to-day miseries of chronic diseases, such as diabetes. They might deliver insulin to initiate cell growth and regenerate tissue at a target location. In case of neurodegenerative diseases such as Parkinson’s, nanodevices could deliver drugs, implant neurostimulators, or transport intelligent biomaterials across the blood–brain barrier in order to direct regeneration within the central nervous system.
2) The greatest chance to treat cancer successfully
As a very simple explanation, cancer occurs when cells refuse to die and keep multiplying in various places in our bodies, while hiding from our immune systems. Currently, the most effective treatments against cancer comprise various forms of radiation and chemotherapy, which stops the regeneration procedure for cells. The problem with chemotherapy and radiation is that it cannot be utilized in targeted ways, therefore it has serious, sometimes even life-threatening side-effects. The use of nanotechnology might mean a revolution in cancer treatment.
Creating drugs that directly attack cancer cells without damaging other tissues has already been proven to be a safe method in treating cervical cancer. Swedish researchers have developed a technique that uses magnetically controlled nanoparticles to force tumor cells to self–destruct without harming surrounding tissue radiation and chemotherapy do. It is primarily intended for cancer treatment, although it could be used for other diseases including type 1 diabetes.
3) Nanoparticles as information managers and surgeons
Nanodevices might be programmed into gathering information about certain body parts, levels of toxins and other substances inside our bodies and then “report” back to the medical professionals or to its “hosts”. In the future, it might become reality that a nanorobot sends alerts to your smartphone that your glucose level is high, you need to take insulin. Nanoparticles might gather in certain tissues and then scan the body with a magnetic resonance imaging (MRI) with the aim of highlighting existing illnesses.
Another group of nanodevices might be programmed to bring certain substances to cells or might be injected into the bloodstream to seek out and remove damaged cells, grow new cells, or perform other procedures. Nanosponges circulating in our bloodstream could absorb and remove toxins.
The John Hopkins University has developed robots only 1 millimeter across that can take biopsies inside the colon. Patients swallow a tiny capsule, and the robotic biopsy comes out with it. Engineers are working on having these robots perform surgery inside the colon, too.
An evil creature will use nanotechnology to control and influence people?
According to optimistic futurists, nanomedicines like smart drugs will lead to the prevention of all illnesses, even aging, making us superhuman from many perspectives. However, as every tool in the hands of humans, nanotechnology also has downsides.
Nanobots are so tiny that it is almost impossible to discover when someone for example puts one into your glass and you swallow it. Some people are afraid that by using such tiny devices, total surveillance would become feasible – since nothing can remain hidden when there is a robot swimming through your bodily fluids. Who and how will use our information? Might there be criminals or terrorists out there who attempt to utilize these nanobots to deliver toxic or even lethal drugs to organs? Should we prepare ourselves again for a new type of terrorism?
Also, while these questions are relevant and might cause some discomfort, there are some bigger questions at stake here with even larger impact. What if there comes a point at which the overlap between nanorobots and our own cells–organic material merging with synthetic ones–becomes problematic? If nanobots can replace cell functions or even the entire cell, then what part of us remains human? What if the army of nanorobots will perfectly merge with our cells and we cannot know anymore to what extent we are humans? We already know that neurons can live in harmony with a biochip and make connections with electrodes. What happens when we and the tiny computers living inside us become one? Do we want to become one in this way?
I think the medical community and also the wider public should get to know the particularities of nanotechnology as soon as possible to be able to prepare in time for the future. I believe that we should also start a discussion about the ethical and philosophical issues concerning nanobots. We should create groups of bioethicists who can help society assess the risks appropriately and help decision-makers to regulate the use of nanotechnology according to the common good.