PSI - Issue 50

E.G. Zemtsova et al. / Procedia Structural Integrity 50 (2023) 307–313 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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1. Introduction The duration of recovery of damaged bone after implantation affects the quality of patient ’s life, therefore, one of the most important factors in implantation is the engraftment rate. This is ensured by the bioactivity of its coating, which is determined by the chemical composition and surface topography. Due to high mechanical characteristics and economic feasibility, implants are most often created on the basis of metals, such as alloys of titanium, cobalt, etc. However, susceptibility to corrosion, to infections, low biological activity and, therefore, the inability to effectively integrate into the hostile environment of the body are the main sources of problems associated with implant rejection. This leads to the development of new bioactive systems for implants Oliver (2019), Murr (2019). Bioactive coatings for metallic implants are being extensively researched because local therapeutic interventions are generally more desirable than systemic treatments due to better bioavailability and rapid bone healing response Gulati (2016). Literature and clinical practice note the relationship between implant surface morphology, biocompatibility, and osseointegration Coelho (2015), Zemtsova (2018), Mendonça (2008) . The bioactive properties of the implant are affected not only by the chemical composition of its coating, but also by the surface topography. It has been clinically and experimentally proven that the presence of a micro-rough implant surface and nanoscale irregularities that mimic the natural structure of the bone provides improved implant osseointegration Wennerberg (2010), Wennerberg (2010), and, consequently, accelerates the bone healing process. Thus, the two-level hierarchy of the coating relief, which is provided by the presence of irregularities in the micron and nanometer range, triggers the osteoblast differentiation and improves adhesion, thus increasing material bioactivity Coelho (2015), Zemtsova (2018), Gittens (2011), Nazarov (2018). However, not all methods make it possible to obtain coverages with a two-level hierarchy, i.e. with micro- and nanoscale structures. The combination of various technological methods (sol-gel technology, etching, laser technologies) is a promising strategy for the production of implants with biologically active coatings, including a combined micro- and nanostructure consisting of inorganic bioactive materials Meirelles (2013). In this work, to obtain a TiO 2 coating with micro- and nano-roughness, the sol-gel technology was used in combination with dip-coating, since this made it possible to apply a coating of a given thickness and structure under standard conditions. The duration of the implant engraftment is also affected by the possibility of infection of the near-implant area Koo (2017). The use of antibiotics in this situation is fraught with the development of bacterial resistance to antibiotic drugs, so it is reasonable to use various organic or inorganic bactericidal coatings. It is important that for implantation such systems need to be not only antibacterial, but also biocompatible, able to support the reproduction and functionality of surrounding tissues Singh (2018). Most inorganic antibacterial agents are metals and metal oxides, in particular silver (Ag), copper (Cu), gold (Au), and zinc (Zn), in their micro- or nanoforms Singh (2018), Saidin (2021). Silver is the most beneficial antibacterial agent, as it is characterized by bactericidal properties of a wide spectrum of action, and a high level of biocompatibility and stability Tian (2016), Campoccia (2013). Its pronounced antifungal and antiseptic abilities are noted. Also, silver exhibits a high level of bactericidal effect on microorganisms resistant to antibiotics. Silver coatings can be synthesized on the implant surface by various methods, such as electrospinning Soo (2020), vapor deposition Soo (2020), layer-by-layer deposition Varghese (2013), vacuum plasma sputtering He (2020), anodizing Liang (2020), electrochemical deposition Morris (2017), Lu (2011) and others. In this work, the method of pulsed electrochemical deposition is used to deposit silver. This method makes it possible to synthesize coatings characterized by a uniform distribution of deposited particles, high adhesion to the titanium surface, and the ability to create coatings of various structures.