Currently, available methods for the prevention and treatment of periprosthetic infection are partially effective, since they do not take into account its pathogenesis associated with the formation of biofilm. The process of formation and development of biofilm begins from the adhesion of microorganisms from the environment to the surface of abiogenic component (endoprosthesis). When there are already adherent forms of bacteria, the conservative tactics of antibiotic therapy is futile. Therefore, current methods for the prevention and treatment of infections associated with the implant should be aimed to inhibiting bacterial adhesion and formation of biofilm. Local protection of the implant can be achieved in various ways, including the use of protective coatings in the form of a gel. In this regard, hydrogels based on polyvinylpyrrolidone have been formed using various technological modes, such as high-energy radiation, heat treatment, and their combination. The mechanisms of hydrogel formation were studied using ATR FTIR spectroscopy. The properties of hydrogels were studied by differential scanning calorimetry and determination of the contact angle. Gelation occurs due to the transformation of linear polyvinylpyrrolidone macromolecules into a network structure. Depending on the used technological method, the mechanisms of hydrogel formation differ: in the case of ɤ-treatment, cross-linking occurs with the participation of carbon atoms in the pyrrolidone ring and the main chain, and also oxygen in the carbonyl group; in the case of heat treatment - with the participation of carbon atoms in the pyrrolidone ring and the main chain. According to the thermophysical characteristics (in particular, according to the values of glass transition temperatures (Tg)) the effect of high temperature on polyvinylpyrrolidone leads to a slightly denser crosslinking than the effect of γ-irradiation, the values of the molecular weights are within the same order of magnitude (M_c(PVP-HT)=1 ,2ˣ10⁴, Mc_(PVP-ɤ) =1.0ˣ10⁴). According to the data of the free energy of the metal surface (NiTi) and the surface tension of gel substances, polyvinylpyrrolidone hydrogels wet the surface of medical NiTi well. There are different theories of adhesion: adsorption, diffusion, chemical theory; microrheological; electric. However, the method of research and calculation of the polar and dispersive components proposed by Owens-Wendt (the concept of additivity of surface interaction components), further developed by Yu.S. Lipatov, who insisted on the prevalence of the dispersive component in the adhesion process, is widely used. The results showed that the good wettability of a metal surface made of NiTi by hydrogels occurs due to the dispersive component, a tight fit should prevent the formation of a biofilm in vivo. Taking into account the obtained results, polyvinylpyrrolidone hydrogels can be recommended for use as an anti-adhesive barrier regarding to metal endoprostheses made of NiTi.

Declaration of interest:
Conflicts of Interest The authors declare that they have no conflict of interest in the publication of this article. Abstract was not submitted elsewhere and published here firstly.