Implant with shape memory
Russian physicists have figured out how to facilitate the work of surgeons
Specialists of the National Research Technological University "MISIS" (NUST MISIS) together with other Russian scientists were able to improve the basic medical material with the shape memory effect. According to the authors, their development will greatly facilitate the work of surgeons and improve the quality of therapy. The study was published in the journal Polymers (Zhukova et al., Polymer Composite Materials Based on Polylactide with a Shape Memory Effect for “Self-Fitting" Bone Implants).
Polylactide is a polymer used in surgery for suture fixation and other auxiliary tasks. It is characterized by high biocompatibility and complete biodegradability, since it consists of lactic acid molecules that play an important role in metabolism. It is produced from cheap vegetable raw materials with a high sugar content.
Polylactide has a pronounced shape memory effect (EPF): after deformation, it is able to quickly return to its original state. Thanks to this, the polymer, according to the scientists of NUST MISIS, is optimally suited for the development of self-installing implants. They are used to treat defects in bones that do not carry a supporting load.
The use of such implants will avoid time-consuming adjustment to the injured area, which will greatly facilitate the work of the surgeon and reduce the operation time, the scientists explained. The product of the required shape can be compressed to a convenient size and placed in the place of the defect, heated – due to the EPF, the implant itself will take the desired position.
Polylactide, according to scientists, has only one noticeable drawback. The temperature at which the shape memory effect is activated (55-65°C) is too high to work with human tissues. Specialists of NUST MISIS have developed a new polymer composite based on polylactide, which takes the old form already at a temperature of 45 ° C, which is quite acceptable with short-term exposure to the body.
"Studies of self-installing implants are carried out mainly on inert polymers, achieving the desired activation temperature of EPF due to chemical crosslinking of polymers and the introduction of additional components. The peculiarity of our work is that we used only biocompatible, biodegradable polymers, having achieved a decrease in temperature due to simple physical mechanisms. This reduces not only the temperature, but also the activation energy," explained Polina Zhukova, an engineer of the NUST MISIS scientific project.
The new material is a polylactide matrix with spherical inclusions of another polymer, polycaprolactone. The material is obtained by extrusion, that is, by mechanical stirring in a hot chamber. NUST MISIS specialists have fully described the parameters of the EPF, thermal and mechanical characteristics of the new composite.
Scientists of the Russian State University named after A.N. Kosygin took part in the work. In the future, the research team plans to increase the regenerative abilities of the material by adding special bioactive ceramics, as well as to develop new non-temperature methods for activating the shape memory effect.
Portal "Eternal youth" http://vechnayamolodost.ru