Created material that excludes tissue rejection during transplantation
Scientists from Russia and the United States have proposed new material for regenerative medicine. The compounds in the composition of this material literally “turn off” the work of enzymes that are responsible for the inflammation reaction that occurs in immune cells in response to external stimuli. The results of the researchers’ work are published in the journal ACS Biomaterials Science & Engineering.
“At the moment, researchers do not have a lot of tools to regulate the immune response in the arsenal. You can work with proteins, but it’s difficult. You can use the compounds to destroy immune cells, but this is fraught with consequences for other cells of the body. We have chosen a different path and suggest using special inhibitor substances built directly into biodegradable material, ”says Ksenia Stankevich, lead author of the article, engineer of the plasma hybrid systems laboratory at Tomsk Polytechnic University.
These three-dimensional frames of thin polymer threads interwoven with each other in different directions are called scaffolds. In regenerative medicine, they are used for injuries of bones and soft tissues. They are placed at the site of the defect, and new tissue grows through this material and regenerates at the site of the injury.
Researchers at TPU and Montana State University used a biodegradable polycaprolactone polymer for their scaffolds. Products from it are quite elastic and inexpensive in comparison with analogues. Scientists synthesized a framework from polycaprolactone by electrospinning: they pulled the finest fibers from a polymer solution, acting on it with an electric field. An innovation was the introduction of an inhibitor into the structure of the scaffold at the stage of its preparation. As such compounds, the scientists chose 11H-indeno1,2-b-quinoxaline-11-onoxime and 11H-indeno1,2-b-quinoxaline-11-one-O- (O-ethylcarboxymethyl) oxime.
“Inhibitors suppress or slow down physiological and physicochemical processes. They act on enzymes. But for this, the enzyme and the inhibitor must come together, like a lock and a key, ”says Stankevich. – One of the groups of enzymes responsible for the inflammatory process is called JNK. Earlier, we received new promising inhibitors that showed high biological activity in suppressing the work of compounds of this group. In a new work, we introduced these substances into the structure of scaffolds and obtained scaffolds that can release inflammatory inhibitors evenly and for a long time. This is mainly due to the gradual natural degradation of the polymer. By the way, it degrades to biocompatible 6-hydroxycaproic acid, which the human body can utilize. ”
This work was carried out on cell lines. In the future, scientists plan to conduct in vivo studies. In the future, such scaffolds could be used to repair defects in soft tissues and blood vessels – for this, polycaprolactone has suitable mechanical properties. Scaffolds from various materials are already being introduced into medical practice in developed countries, but it is too early to talk about their widespread use.