Scientists of the research center “Physical Materials Science and Composite Materials” of the Tomsk Polytechnic University received biodegradable polymer for regenerative medicine. The results of the research are published in the journal Materials Letters.
According to the creators, this material is able to dissolve in the human body with time. At the same time, it is a good piezoelectric, that is, under mechanical influence it is capable of producing an electric charge that helps to activate the functional features of the cell, stimulates the regeneration of tissues. Piezoelectric materials are capable of producing a charge without an external source of electrical energy. The charge on their surface is formed under the influence of external mechanical action, that is, if the material, for example, is compressed, twisted, squeezed.
The piezoelectric effect is widely studied today for use in regenerative medicine, as previous studies have shown that piezoelectrics enhance tissue regeneration. The charge on their surface interacts with the charge of the cell membrane, and this electrical impulse stimulates the functional characteristics of the cell. With the help of piezoelectrics one can even control living cells, attracting and moving them under the action of a charge.
“The strongest piezoelectrics are undegradable. And for regenerative medicine this is one of the key properties. The material must be degradable in order to dissolve in the body with time, and that new cells should take its place. Otherwise, the person will have to do one more operation and remove the implant. Therefore, scientists are now looking for materials that would have been piezoelectric, and at the same time degraded.
We proposed our hybrid material connecting two polymers, degradable polyhydroxybutyrate and piezoelectric polyaniline, “says Roman Chernozem, a member of the research team at the Research Center for Physical Materials Science and Composite Materials, TPU.
Polytechnics dissolved the initial polymers polyhydroxybutyrate and polyaniline, and a hybrid polymer was obtained from this solution by electroforming. It consists of interwoven fibers of raw materials. The fiber sizes can be varied from 300 nanometers to 10 micrometers. The resulting hybrid material is a flexible and porous “scaffold” – a design that mimics an external cellular matrix.
“The experimental part of the work showed that to add piezoelectric properties to the material, to increase piezoconstant several times, it is enough to add only 2% of polyaniline from the total mass. This turned out to be the optimal combination, because if the content of polyaniline is increased, the piezoelectric effect on the contrary decreases, – the researcher notes. – In addition, the addition of polyaniline leads to improved mechanical properties, the polymer stretches better. This is important if you use it for manufacturing, for example, wound dressings. ”
According to scientists, the use of such a hybrid polymer can be used as a material for bone implants to replace bone defects, restore nerves and as a dressing for wounds.
“The advantage of polymers over the same piezoelectric ceramic used in medicine, in their mechanical properties, they are elastic. The surgeon can cut off the “patch” with a scissors on the spot for the bone defect of a particular patient, “Roman Chernozem adds.