[Experimental morphological rationale for the use of cultures of multipotent mesenchymal stem cells in combination with biomaterials in the reconstruction of the pelvic floor].

To date, descension of the pelvic floor is a fairly common gynecological pathology that requires surgical treatment. The development of cellular technologies suggests that the use of multipotent mesenchymal stem cells (MMSC) in the treatment of this pathology can stimulate the regeneration of damaged tissue and contribute to the reconstruction of the structures of the pelvic floor. OBJECTIVE: to evaluate the effectiveness of using MMSC in combination with biological and synthetic materials in vitro and in vivo with descension of the pelvic floor. MATERIALS AND METHODS: Sprague Dawley rats 10 weeks old weighing 200 grams were used in the experiment. Under sterile conditions, mechanical damage to the posterior wall of the vagina was carried out, with the restoration of which vicryl 3-0 was used. On the 2nd and 4th day, the wound was cut off in a volume of 1.5 ml with xenograft, allograft and multipotent mesenchymal stem cells (MMSC) (5 thousand cells) obtained from the adipose tissue of rats. In the control group was not used biological material. At the second stage of the experiment, the compatibility of the mesh prosthesis with MMSC and allograft in vitro was evaluated. RESULTS AND DISCUSSION: xenograft does not lead to full tissue regeneration, but contributes to rapid epithelialization and reduces the degree of inflammatory reaction in the wound during the regeneration of connective tissue. The use of allograft leads to quick and complete epithelialization of the wound and the formation of a structurally complete connective tissue lamina of the vaginal mucosa. The introduction of MMSC resulted in complete epithelialization of the wound and the formation of a structurally complete connective tissue plate of the mucosa and submucosa, but with a slightly smaller number of blood vessels in them than with the use of a biomaterial. At the second stage of the experiment, weak cell adhesion to the polypropylene substrate of the tablet was observed during cell culture in the presence of only a fragment of the mesh prosthesis. After MMSC cultivation in the presence of a mesh prosthesis fragment and an allograft, a relatively uniform distribution of cells around the mesh prosthesis loops was observed. CONCLUSIONS: it was determined that the use of MMSC and allograft has a positive effect on the process of vaginal tissue regeneration in rats. When combining these materials with mesh prostheses, it was found that MMSCs are not fixed directly to the synthetic material, but when the allograft is added, they concentrate and presumably have the maximum anti-inflammatory effect and promote tissue regeneration at the site of the mesh prosthesis. Thus, the use of autologous MMSC cells in combination with allograft and mesh polymeric materials for pelvic floor reconstruction can significantly improve the results of reconstructive operations.

[Effect of radiation sterilization on biomaterial structure and properties].

The purpose of the investigation was the study of structural changes connective tissue biomaterials after different combinations of their radiation sterilization, physico-chemical treatment and conservation. Using a complex of histological methods (polarization microscopy of unstained sections, van Gieson's stain, scanning electron microscopy), an analysis was performed to detect the structural changes in tendons and dermis which underwent various physico-chemical treatment and subjected to the radiation sterilization using different types (3- radiation and fast-moving electron stream) and doses (1.5, 2.5 and 4 Mrad) of radiation. The dependence of the structural changes in the biomaterials on the fibroarchitectonics of the tissue as well as on the physico-chemical treatment and radiation type and dose was demonstrated. The tendons underwent clear-cut significant changes in all regimes and radiation doses studied. Dermis was found to be most resistant to radiation challenge.

The role of macrophages in the tissues regeneration stimulated by the biomaterials.

Allogenic grafted tissues are subjected to biodegradation and replaced by the regenerate. To minimize the immune response and improve the rebuilding of tissues there was developed a technology to treat tissues with a cells elimination and dosed out extraction of proteoglycanes (Alloplant. With aim to clarify the role of macrophages in the tissues regeneration resulting implantation the biomaterials 112 rats were injected the allogenic and xenogenic (rabbit's) pulverized biomaterials in the form of suspension. Injections were performed subcutaneously into the animals' back by the base of the tail. The control group (14 rats) were injected a physiologic saline. Animals were killed by ether inhalation on day 2, 4, 7, 14, 30, 90 and 180 and tissue sections were studied by light and electron microscopy. The study showed the key role of the macrophages in resorption of the allogenic biomaterial and formation of the newly-formed tissue. Implantation of the biomaterial induced activity a great number of the mature macrophages, which completely lysed and resorbed the biomaterial particles. Expression TNFalpha was significantly higher whereas expression TGF-beta1 was significantly lower. With xenogenic biomaterial implantation there were less macrophages, their activity was restricted. Macrophages containing large vacuoles with an active endo- and exocytosis were revealed in the allogenic biomaterial implantation and were named 'matrix-forming macrophages'. We may suppose that these macrophages synthesize (or re-synthesize) proteoglycan component of the newly-formed collagen fibers. There was put forward a hypothesis about the two component mechanism of the collagen fibers formation.