For the first time, Tomsk implants made of titanium nickelide can be implanted to a patient abroad: as part of the MegaGrants led by Alexey Volynsky, professor from the USA, research will be performed for their wide application throughout the world. This is how implants attracted a well-known materials scientist to Tomsk State University and why he became proud of his homeland in Siberia.
Service life is life.
When a foreign body gets inside the human body, the “friend or foe” recognition system immediately triggers the process of “expulsion” of the alien. Even a small splinter causes an inflammation foci, to say nothing of the implants, for example, fragments of bone or joints. Therefore, their biocompatibility is the focus of the study by leading materials scientists all over the world.
Alexey Volynsky, professor of the Department of Engineering Mechanics, the University of South Florida, a specialist in the field of surface engineering of biomaterials, came to Tomsk to lead the TSU MegaGrants on this topic. He shows some metal products – one is rough, the other one is smooth, and the third one is woven in the form of a grid. It could be part of a bone, it could be a new vertebra, it could be a repaired fragment of a vessel or tendon…
“They are all made of titanium nickelide, a shape memory material. It is not toxic like cobalt alloys. Unlike polymer products, it is compatible. Moreover, it exhibits unique mechanical properties; it is more difficult to destroy than any other material, even in an aggressive corrosive environment”, Volynsky said.
The implant structure is determined by the technology of its production. For example, a highly porous bone replacement material is fabricated by SHS synthesis. Due to the surface properties, biological tissue easily grows into it, and the body recognizes the implant as its own.
Ekaterina Marchenko, head of the Laboratory for Medical Alloys and Shape Memory Implants, TSU, added: “For successful implant functioning in the body, it must be rheologically compatible with biological tissues. That is, it must show a similar behavior, be the same durable.”
“Alloys developed in our laboratory are superelastic, they relax internal stresses due to reversible martensitic transformations. Thus, in experiments in vivo, we have shown that porous titanium nickelide can withstand more than 15 million cycles of bending and tensile loads,” Marchenko explained. “Due to the viscoelastic hysteresis behavior, the implant deforms together with the living biological tissues in which it is integrated. High cyclic endurance allows implants made of porous titanium nickelide alloy to function safely throughout life.”
She said that the study of titanium nickelide alloys at TSU was started by Victor Günther 30 years ago. Many operations have already been performed on people, for example, Tomsk surgeons installed such implants in patients who lost extensive bone fragments due to oncology. Their Krasnoyarsk colleagues replaced titanium plates in the spine of patients by titanium nickelide alloys, because under dynamic load they failed and poisoned the tissues with decay products.
Though, there is one “but”: scientists have not yet formulated the criteria for rheological compatibility, and the alloy for a particular operation is chosen with regard to subjective experience of experts. A team of physicists, materials scientists and biologists, together with Professor Volynsky, will develop these objective criteria.
Breakthrough of the Motherland
Alexey Volynsky, as a well-known materials science specialist, often receives letters from younger colleagues with a request to support one or another project for grant application. Once, he received such a letter from Tomsk.
“The topic is interesting, the team had many publications on it – for example, back in 1999, TSU professor Yuri Chumlyakov published a paper on titanium nickelide in Acta Materialia, the leading scientific journal. I agreed. It usually does not work, but to my surprise, we won a MegaGrant. It is very prestigious, there are only 43 of them in Russia. I am glad and grateful that finally my experience and knowledge came in handy in my homeland,” Volynsky says.
The total value of the MegaGrant is 90 million rubles for three years, which is a large amount even by American standards.
One of the MegaGrant terms says that the study should be led by a foreign scientist with high h-index and citation, who is expected to stay with his research team for at least 90 days a year. This summer Alexey Volynsky came to Tomsk for the first time. He has not been to Russia for ten years.
“To be honest, I was pleasantly surprised by how good it is here – what a comfortable environment and delicious food, how friendly Siberians are, and what a high level of research. The people who “came out of the Redland” (I’d use this expression) still look on the dark side of things –TV in America puts a negative spin on the country. I post photos for groups of emigrants accounting for 20 thousand followers, I got haters,” the scientist smiles.
He himself is a classic example of “the departed”. In 1989, he joined an exchange group from the Moscow English specialized school and went to the United States. In 1994, being the student of the Moscow Aviation Institute of Technology, he also participated in an exchange program to do studies at the University of Pennsylvania. In 1996, when science in Russia, as he saw it, got ruined, he decided to leave and do the PhD program in the University of Minnesota.
“My area of interest lies at the intersection between materials science and mechanics. In 2000, I defended my PhD thesis on adhesion (adhesion of surfaces) of thin metal films to ceramic substrates. I did internship at Motorola – my work was in demand at the time when they were switching from aluminum contacts in microprocessors to copper ones, and adhesion measurement methods were needed. We developed them in the group of my boss Bill Gerberich, so after internship I got a job at Motorola,” Volynsky says.
In 2003, he moved to the University of South Florida and worked in the Department of Mechanical Engineering. In 2010, he decided to go back home…
“Once every seven years I had an annual sabbatical, and I came to Moscow and tried to get a job. Nothing came of it! I met cool managers from state corporations; they looked through my resume and said: “We’ve never had such specialists…, and we do not need to!” I said to myself then that I would never come back again. Now, I’m really proud of Russia, where such projects are being developed, and the government is investing in science,” the scientist says.
Got something to say to the world
Alexey Volynsky is convinced that Russia has always shown advances in science. However, globally, an indicator of research effectiveness implies, first, the number of scientific publications, second, and most importantly, the number of citations. According to these indicators, Russia is still lagging – it is about to conclude the world top 10. The leader is China.
“I published the first paper in Acta Materialia on the topic of my PhD dissertation. In 2004, I received a letter from Web of Science that scored the largest number of citations in the field of materials science in a month it – the number of citations gained attained 689,” Volynsky says. “China started publishing articles in scientific journals on an industrial scale 15–20 years ago. In 2020, it published more articles than America. In Russia, this process was launched 5–10 years ago. Foreign journals have strict requirements to the article quality and design, so my 25-year experience of publishing in foreign scientific literature will be appropriate in Tomsk.”
He adds, “Mind you, to estimate a scientist by the number of papers is “pure bookkeeping, not real life”:
“In America, a professor normally publishes two papers a year. The publishing cost for one paper is about 100 thousand dollars. We have a MegaGrant plan of 5–7 papers per year, and this is a lot: conducting research, data processing and publishing makes a complex and lengthy cycle.
On the other hand, Tomsk scientists have a high chance of publishing in high-ranking journals: titanium nickelide is a rather long-explored subject; however, there are only 300 articles on it in the Web of Science database. Perhaps, because this is a semi-commercial story – mainly industrial companies are engaged in research.”
“Our first papers within the framework of the MegaGrant will be written in collaboration with doctors who use the material for reconstructive facial surgery (in particular, with Evgeny Bogdanovich Topolnitsky, doctor of medicine, a leading oncologist from Siberian State Medical University). The operations were preceded by animal studies, and this, by the way, is beneficial for Russian science: it is extremely difficult to conduct them in the States – obtaining permission for experimenting with mice at my university takes about two years,” Volynsky notes.
He says that further the team will conduct and publish the findings of the basic research:
“Our main task is to describe the fundamental principles of the interaction of materials and tissues. We will develop scientific criteria for the surgeon to assess the appropriateness of the material for some particular tissue with some particular properties. The project will yield the guideline for use based on biomechanical similarity. This would allow the development to be widely used in practice, and not only in Russia. Thus, a year ago in Israel, I met Dr. Sela, who restored the face of an Arab who lost part of his facial bone due to a gunshot wound. For two years, he has been implanting hard plates, but they do not survive, the patient is suffering… I sent our paper about titanium nickelide implants to the doctor, and he got interested; perhaps, cooperation would start. This is truly world class.”
Author: Elene Tailasheva
Source: RIA Tomsk