The website of the Ministry of Science and Higher Education of the Russian Federation has posted a research paper on the developments of SSU scientists. It is titled the New Smart Materials for Tissue Engineering Produced in Saratov.
Scientists at the University of Saratov continue to actively develop promising technologies for the manufacture of medical nanomaterials. Thus, the results of two experimental studies at once, carried out with the participation of a group of SSU employees, headed by the head of the Department of Radio Engineering and Electrodynamics, O.E. Glukhova, published in prestigious scientific journals.
On the pages of "Composite Structures" you can get acquainted with the results of the joint work of the employees of the Department of Radiotechnology and Electrodynamics and the Division of Mathematic Modelling of SSU Education and Research Institute of Nanostructures and Biosystems, the Moscow Institute of Electronic Technology and the First Medical University named after I.М. Sechenov. Scientists have developed a laser technology for fabricating structures in the form of composite layers based on carbon nanotubes and biopolymers, including macromolecules of albumin, collagen and chitosan. Such structures are intended for the manufacture of devices and implants for the cardiovascular system. In the course of their work, the researchers identified the optimal parameters of laser action for the formation of composite biopolymers that conduct electrical impulses and have a mechanical hardness of layers above 100 MPa.
As the head of the department of radio engineering and electrodynamics of SSU O.E. Glukhov, the article contains the results of three years of theoretical and experimental research describing the full cycle of manufacturing new nanomaterials for the creation of medical tissue-engineering structures. The films of the produced nanomaterial are populated with special cells, after which the implant is inserted into the area of the defect in the tissues of the heart or blood vessels.
Among the key advantages of the formed biopolymers are the ability to ensure a normal level of hemolysis when interacting with erythrocytes and high biocompatibility with endothelial cells lining the inner surface of blood vessels. According to the professor, the new materials could be used to create smart coatings for the surfaces of cardiovascular implants in contact with blood, such as pumps for pumping blood.
“Here the word“ smart ”is understood in the well-known meaning of“ smart ”. This material makes this material its controlled structure, characterized by a bimodal pore distribution. Small pores - 1–5 µm in size - are involved in the processes of vascularization (formation of new blood vessels) and innervation (supply of nerve cells). In turn, large pores - 100-200 µm in size - are involved in cell proliferation (growth and division). It should be noted that the pore size can be, as it were, "tuned" by selecting the sizes of single-walled carbon tubes and their beams in the initial dispersion, from which a solid nanomaterial with a branched nanostructure is formed by laser action. Pore size control is additionally provided by calculating the threshold energy density of laser pulses based on nonlinear optical interaction of radiation with SWCNTs [single-walled carbon nanotubes], ”Olga Evgenievna explained.
Thus, the staff of the Department of Radiotechnology and Electrodynamics and the Division of Mathematic Modelling of SSU Education and Research Institute of Nanostructures and Biosystems "tune" the structure and properties of the nanomaterial being created - in particular, as a result of long-term numerical experiments, the sizes of nanotubes and their structure, as well as the wavelength of the laser irradiating them, are preliminary revealed. These procedures are carried out using modern quantum simulation methods using high-performance computing. The next stage includes the process of synthesizing nanomaterials based on theoretical results. This part is implemented by A.Yu. Gerasimenko, who is currently working on his doctoral dissertation with the scientific advice of Professor O.E. Glukhova. The final phase, which includes biological and medical research, is carried out by scientists of the I.M. Sechenov.
Experts emphasize that work on new smart materials for tissue engineering continues - in particular, in the field of neuronal proliferation, the development of new drug delivery systems and the creation of artificial muscles to solve the problems of modern bionics. The results of research carried out in this direction formed the basis of the publication, placed on the pages of the journal "Molecules". Using a combination of various methods of mathematical modeling, the research team of Professor O.E. Glukhovoy evaluated the mechanical and electronic properties of a composite based on two graphene flakes and DPPC phospholipid molecules between them.
“Phospholipids, which make up one third of all lipids in human blood, are used in various drug delivery systems, but when they enter the bloodstream, such systems experience abnormally high stress. To protect medicinal carriers from dangerous external influences, graphene is used, which is the most durable material known today. The object of our research was a composite, which is a layer of phospholipid molecules enclosed between graphene layers. The strength of such a layered polymer system was estimated using "virtual nanoindentation" using a numerical experiment based on the method of molecular dynamics, "Olga Evgenievna said. The essence of the method used was as follows: a nanoindenter in the form of a carbon nanotube with a time step of 0.0001 nanoseconds was brought closer to the surface of the object under study, inducing structural changes in it. As a result of the experiment, it was found that under such an effect, the region of maximum local stresses is concentrated on graphene atoms, which thus protect the phospholipid molecules from possible destruction.
O.E. Glukhova added that the revealed by scientists effects of "hardening" of phospholipid by graphene layers can be used not only for the development of new drug delivery systems, but also for the creation of new generation electrochemical biosensors.