The coating formation technique for artificial knee ligaments was proposed, which provided tight fixation of ligaments of polyethylene terephthalate (PET) fibers as a result of the healing of the bone channel in the short-term period after implantation. The coating is a frame structure of single-walled carbon nanotubes (SWCNT) in a collagen matrix, which is formed by layer-by-layer solidification of an aqueous dispersion of SWCNT with collagen during spin coating and controlled irradiation with IR radiation. Quantum mechanical method SCC DFTB, with a self-consistent charge, was used. It is based on the density functional theory and the tight-binding approximation. The method established the optimal temperature and time for the formation of the equilibrium configurations of the SWCNT/collagen type II complexes to ensure maximum binding energies between the nanotube and the collagen. The highest binding energies were observed in complexes with SWCNT nanometer diameter in comparison with subnanometer SWCNT. The coating had a porous structure—pore size was 0.5—6 μm. The process of reducing the mass and volume of the coating with the initial biodegradation of collagen after contact with blood plasma was demonstrated. This is proved by exceeding the intensity of the SWCNT peaks G and D after contact with the blood serum in the Raman spectrum and by decreasing the intensity of the main collagen bands in the SWCNT/collagen complex frame coating. The number of pores and their size increased to 20 μm. The modification of the PET tape with the SWCNT/collagen coating allowed to increase its hydrophilicity by 1.7 times compared to the original PET fibers and by 1.3 times compared to the collagen coating. A reduced hemolysis level of the PET tape coated with SWCNT/collagen was achieved. The SWCNT/collagen coating provided 2.2 times less hemolysis than an uncoated PET implant. MicroCT showed the effective formation of new bone and dense connective tissue around the implant. A decrease in channel diameter from 2.5 to 1.7 mm was detected at three and, especially, six months after implantation of a PET tape with SWCNT/collagen coating. MicroCT allowed us to identify areas for histological sections, which demonstrated the favorable interaction of the PET tape with the surrounding tissues. In the case of using the PET tape coated with SWCNT/collagen, more active growth of connective tissue with mature collagen fibers in the area of implantation was observed than in the case of only collagen coating. The stimulating effect of SWCNT/collagen on the formation of bone trabeculae around and inside the PET tape was evident in three and six months after implantation. Thus, a PET tape with SWCNT/collagen coating has osteoconductivity as well as a high level of hydrophilicity and hemocompatibility.

Introduction Osteoarthritis (OA) is a common polyetiological disease of the musculoskeletal system, leading to disability. The condition can prevent a person from work, affect mental health, increasing mortality and affecting health care resources around the world as a current and future disease burden. OA had been considered an aseptic disease in the past and now the microbiological factor is viewed as one of the significant etiological aspects of the condition.The objective was to summarize the literature data on the role of microorganisms in the etiology and pathogenesis of osteoarthritis, including concomitant HIV infection.Material and methods The original literature search (2010 to 2023) was conducted on key resources including Scientific Electronic Library (www.elibrary.ru) and the National Library of Medicine (www.pubmed.org). Literature searches included both Russian and English studies reporting the effect of microbiological factors on the development of arthropathy.Results and discussion New, more advanced microbiological diagnostic methods have been used. There has been evidence of a variety of microorganisms including pathogenic and opportunistic pathogens in the absence of clinical and radiological signs of arthritis. This changes ideas about the etiology and pathogenesis of degenerative processes in the articular cartilage and necessitates a revision of treatment protocols for some joint diseases. Multicenter comprehensive studies of the microbiome of joint formations, blood and intestines are needed.Conclusions The presence of pathogenic microflora in the joint structures is evident in a significant number of observations. There is evidence of a local infectious process in the local cellular elements of osteochondral tissue in patients with previously diagnosed aseptic osteoarthritis. Intestinal microbiomes and the urogenital tract are most common sources of infection. A local influence of the immunodeficiency virus on the development of osteonecrotic processes in joint formations can be suggested in HIV patients.

A study of solid-phase structures of blood serum using wedge-shaped and marginal dehydration methods (Litos system technology) was conducted in order to find out the causes of an inflammatory reaction followed by fibrosis in the second operated joint in a patient with bilateral knee arthritis. The study was aimed at identifying specific morphological markers that characterize the bodys response to the endoprosthesis material. Its solid-phase structures indicated the activation of a hyperergic reaction with daily incubation of blood serum with an alloy of titanium, aluminum, and vanadium. On the contrary, the immunological activity of blood serum can be suppressed and the structures present in it can be transformed into amorphous detritus with the incubation of an alloy of cobalt, chromium, and molybdenum. It was observed from the study that the nature of the immunological reaction of a sensitized organism depends on the type of metals that are part of the endoprosthesis. The immune response causes inflammation of the periarticular tissue, followed by its fibrosation and the formation of a scar demarcation shell that separates the periarticular tissue from the endoprosthesis and performs the function of an immunological barrier on the alloy of titanium, aluminum, and vanadium. On the other hand, an immunological reaction causes the destruction of inflamed periarticular tissue, followed by gradual destruction of the articular bag on the alloy of cobalt, chromium, and molybdenum.

Background. Alkaptonuria is an orphan, autosomal recessive disease in which clinical symptoms debut in adulthood and are characterized by progressive degenerative changes in large joints (knee, hip, shoulder) and the spine, often leading to the need for joint replacement. Developing changes often lead to persistent disability. The purpose of this study was to evaluate disability among adult patients with alkaptonuria. Materials and methods. The study included 46 adult patients (31 m 67.4% and 15 w 32.6%) with a reliable diagnosis of alkaptonuria at the age of 20 to 76 years (avg age 56.83 10.52). The assessment of the presence of a disability group at the time of patients treatment to a rheumatologist was carried out. Results. It turned out that disability was determined in 34 (75.6%) patients, there were no signs of persistent disability in 11 patients (24.4%). Among the patients who had signs of persistent disability, most often during the survey period, group 2 disability was established (61.8%), the differences between this and other groups were statistically significant (p 0.05). For the first time, disability in the study cohort of patients was established at the age of 31 to 59 years (the average age was 50.83 5.5 years). Conclusions. It is important to note that in the vast majority of cases, persistent disability occurs in patients who were of working age, which underscores the importance of alkaptonuria as a medical and social problem.