American chemist Chad Mirkin, who received the RUSNANOPRIZE award this year, told RIA Novosti about how his nanoparticles will open the age of genetic medicine, smooth out wrinkles on women's faces and cure us of cancer, and also shared his thoughts on how when nanomachines can destroy the world.
Chad Mirkin is one of the leading American chemists involved in the development of nanoparticles assembled from spherical DNA molecules and combinations of DNA or RNA with metals and other inorganic matter. In addition to "organic" nanotechnology, Mirkin is actively working on the development of technologies for "printing" nanostructures, which can be used to manufacture electronics and optical devices.
Mirkin was considered one of the main contenders for the 2013 Nobel Prize in Chemistry, and has also been nominated in the past for the RUSNANOPRIZE prize, which has been awarded by Rusnano since 2009 for scientific and technological developments or inventions in the field of nanotechnology that have already been introduced into mass production.
Chad, geneticists often face acute social rejection when developing GMOs or gene therapy, but nanotechnology in general and the nanoparticles based on spherical DNA molecules that you have developed do not have this problem. Why it happens?
- In this case, in my opinion, there is a fundamental difference between the creation of nanoparticles and the development of genetically modified products. The study of the properties and the creation of nanoparticles, first of all, belongs to the number of chemical studies, they can be called the results of the search for new and useful properties in some structures that do not exist in nature or are the result of miniaturization, using a variety of methods for their creation.
For example, all materials change their properties when miniaturized. Gold, in particular, loses its golden color and turns red at the nanoscale. This is exactly why nanotechnology is so interesting to us. All these differences that arise during the transition to the nanoscale can be used to develop new, previously unseen technologies.
On the other hand, DNA editing has been implemented globally, using specific biochemical processes, the consequences of which are very clearly defined and which forever change the way living organisms work. This creates ethical dilemmas and attracts the attention of regulators and people concerned about the long-term consequences of such experiences.
Of course, there are people who are afraid of the further development of nanotechnology, but for the above reasons, it is extremely difficult (and dishonest for us) to bring all nanoparticles to the same size and make unambiguous "conclusions" that absolutely all nanotechnologies are bad by definition. If you think about it, the very concept of "nanotechnology" can include almost everything that science has created in recent years. Moreover, if you just look at "ordinary" chemistry, then it operates with molecules whose dimensions are smaller than those structures that we call nanomaterials.
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For example, what we have created, strictly speaking, are not nanoparticles, but, as I like to call them, "spherical nucleic acids", a new type of nanostructures that we create by putting short DNA and RNA molecules onto templates of a certain shape and design … They have no natural equivalents, but at the same time they interact with living matter and cells in an extremely unusual and, importantly, useful way. They can be said to be a triumphant fusion of chemistry, biology and nanotechnology.
Such nanoparticles can be used to solve a host of problems - they can be used to deliver drugs to cells, cure cancer and repair its cells, diagnose diseases and other things. Of course, you can adapt them for harm, but that's not what we do at Northwestern University.
You have already been named as one of the candidates for the Nobel Prize in the past, and this year it was awarded for one of the key discoveries in the field of nanotechnology. Don't you think that you have been undeservedly forgotten?
- In fact, this year the prize was awarded for a discovery that has nothing to do with our research - it was received, among other things, by one of my university colleagues, Fraser Stoddart. Feringa, Savage, and Stoddart worked to create molecular machines - extremely crude miniature analogs of mechanical rotors and switches, capable of performing the same tasks as conventional machines, but at the nanoscale.
We can say that the "Nobel Prize" went to nanotechnology, but you need to understand that this area of science is very broad and includes a very wide range of problems, from environmental protection, medicine and ending with energy and electronics. In this case, these nanotechnologies are very far from what we are doing.
If we talk about the Nobel Prize, then I can't say anything - it's not my prerogative to decide who should receive it, let the experts of the Nobel Committee do it.
One of this year's award winners, Ben Feringa, believes that nanomachines are unlikely to ever threaten humanity. What is your opinion on this issue that people think about first when thinking about the dangers of nanotechnology?
- Again, if you pay attention to what they gave the Nobel Prize this year, you can see that it was awarded for a very fundamental discovery. I think that we are now at the very early stage of the chemical evolution of nanotechnology, which is very far from the capabilities of the machines described in the famous scenario of "gray goo".
In fact, the very idea that machines can spiral out of control and revolt is pure science fiction that has nothing to do with science. I think that it will remain within the framework of fiction for a long time to come. What we are working with and on today is not at all similar to what is needed for such a scenario of the “end of the world”.
The machines that Feringa and colleagues have created are very schematic and do not at all resemble the "nano-terminators" with which science fiction writers scare us. We still have at least decades, if not centuries, before such a scenario becomes the subject of serious discussion.
In which areas of nanotechnology do you expect the most significant breakthroughs in the near future?
“Our nanospherical nucleic acids will be and are already being used for a variety of purposes and in a wide variety of fields of science, medicine and industry. They are already being used for diagnostics in medicine - for example, we have created nanoparticles with gold nuclei covered with a DNA “fur coat”, which are used as tags for an ultra-precise search for specific segments of DNA, proteins and other biomolecules associated with diseases and various bio - "targets".
Such particles can be used for rapid analysis of saliva, blood or urine samples and search for various viruses, bacteria, or even genetically determined diseases in them. All this, I emphasize, is already being used in practice.
In the future, there is more to come - we are creating hollow DNA nanoparticles filled with drugs or some other substance that can penetrate cells, which ordinary DNA and RNA molecules cannot. Such nanoparticles, for example, can be added to skin cream and used to treat over 200 skin diseases associated with DNA breakdowns. Likewise, we can fight colitis, diseases of the eyes, bladder or lungs. The era of genetic medicine is coming.
It is worth understanding here that three things are needed to be successful in this area. First, you need to be able to make RNA and DNA molecules, and we have been doing this task well for 30 years. Second, you need to understand why mutations in certain genes cause disease. This problem was solved in the early 2000s, when the decoding of the human genome was completed.
However, the third thing was missing until recently - the ability to introduce DNA and RNA into those tissues and organs where they should go. And it turned out that nanoparticles are the most convenient and reliable way to solve this problem. Our spherical nucleic acids were able to penetrate cells as easily as no other retrovirus could.
Now we have the opportunity to point-wise inject DNA into the organs that interest us, and not just into the liver, as before, and this has opened up for us previously unthinkable prospects for gene therapy. We do not even need the selectivity of the drug, since we can directly inject DNA where we need it, and not pass through the entire body.
One of your most famous discoveries is the creation of crystals from DNA. Have you found any industrial application for such structures, or is this a fundamental discovery?
- Crystals from DNA are one of the most interesting things that we have been able to create. If there was a "Nobel Prize" for nanotechnology, then the methodology for their production, in my opinion, would be most worthy of it.
We became interested in these crystals back in 1996 for reasons far from medicine and biology. We tested a concept that was new at that time, stating that nanoparticles can be considered as a kind of artificial atoms, and DNA in this case acted as a kind of programmable "subatomic" particles, on the basis of which nanoparticles, "atoms", whose chemical properties were determined would be DNA molecules on their surface.
The flexibility of the properties of such nanoparticles made it possible for us to literally design crystals with a given structure, assembling them atomic atomic with subnanometer precision, including creating such crystal lattices, the analogues of which do not exist in nature. Over the years, we have created 500 different versions of these gratings, six of which are completely artificial. This paves the way for total control over material properties and an endless variety of artificial crystalline materials.
From the point of view of their practical application, we are still only moving in this direction. The first catalysts and optical devices based on these crystals, in my opinion, will appear in about 10 years. It is important that and as in the case of modern electronics, the creation of which was impossible without the ability to manufacture silicon single crystals, the creation of DNA crystals opens the way for a new class of technologies.
When you talked about creating nanospheres from DNA molecules, you said that they can be used for a variety of purposes, including to smooth out wrinkles. Were cosmetic companies interested in this development?
- Yes, many companies have already shown interest in this application of spherical DNA molecules. From the point of view of cosmetology, the potential of nanoparticles is almost unlimited - with their help we can make the skin more elastic, remove dark spots, cleanse cells of pigment molecules and make the skin stop producing them, and also solve a lot of other problems.
But there is a big problem here - it is not clear how the safety of such products will be assessed and regulated by the competent authorities, since they can simultaneously solve both pharmaceutical and cosmetic problems. Who will be responsible for their verification and how it will be done is not yet clear.
In addition, from the point of view of business development and simply from a common human point of view, the development of cosmetics based on nanoparticles from DNA is a secondary task compared to the creation of vaccines against cancer and genetic diseases, which hundreds of thousands and millions of people expect to get rid of.
In recent years, scientists have written hundreds, maybe thousands of articles devoted to the next "materials of the future" - for example, plasmons or DNA origami. Over time, the excitement subsided, but we have not yet seen any visible results. Why it happens?
- In fact, I would not say that all these technologies have evaporated or disappeared - research continues, at least in plasmonics, publications appear from time to time on origami, although there seem to be no technological prospects here. In the short term, both of these materials seem to be only the subject of basic research.
Here it is worth remembering the history of the invention of the laser. When physicists created the first lasers, someone said that "this is an interesting discovery that still awaits its practical application." Today, lasers can be found everywhere - lasers are in every supermarket, they are used to stitch and cut tissue during operations, and are in every computer and communication system.
In other words, often after a fundamental discovery, not even weeks or months, but decades pass before it finds its practical and commercial application.
