Introduction: Mesenchymal multipotent stromal cells (mesenchymal stem cells-MSCs) are currently the most promising and widely used means of cell therapy. Common sources for obtaining them are bone marrow and adipose tissue, but now the umbilical cord and placenta are gaining more and more popularity, since the cells isolated from them have a number of advantages over other sources. Aim: To study the peculiarities of human umbilical cord MSCs influence of on the regeneration of the mucous membrane of the nasal cavity in experimentally induced atrophy. Materials and methods: 30 laboratory mice were observed, which divided into two experimental groups (10 animals each) and control group (10 mice). Clinical and morphological studies were perfoemed 1 and 2 months after the development of atrophic rhinitis. Results: Umbilical cords were obtained after timely delivery, chopped into small fragments and cultured in the appropriate nutrient medium with all supplements known for MSCs. MSCs migrated from the pieces, formed colonies, and after the formation of a 70-80% confluent layer, they were detached from the surface in the usual way and transferred to new vials. This procedure was performed twice, after which the cells were characterized by surface markers (positive and negative for MSCs) and used for administration to model animals. Atrophic rhinitis in mice was developed using 3 pathogenic strains of Pasteruella and confirmed by clinical and morphological characteristics. MSCs (characterized, at the 2nd passage) were injected intravenously (1×106 per mouse) and experimental animals were observed for 2 months. The clinical condition of the animals was examined once a week. After the end of the experiment, a postmortem morphological study was performed. Clinical and morphological data showed positive effect of transplantation of human umbilical cord MSCs for nasal mucosa regeneration in mice compared to untreated controls.
Introduction: Every year, a large number of patients from developed countries turn to surgical departments with the reconstruction problems of the auricle cartilage. A some of surgical procedures was developed to correct minor defects due to the low regenerative capacity of elastic cartilage. Stem cells can potentially differentiate into chondroblasts and chondrocytes and restore cartilage integrity. Many factors influence on the differentiation and proliferation of stem cells, which complicates the method application. Therefore, the investigation of using stem cells to regeneration elastic cartilage is relevant. Aim: clarification the regeneration features of the artificial defect of the rabbits’ ear elastic cartilage after the stem cells injection. Materials and methods: The investigation was conducted on rabbits of chinchilla breed aged 1.5 months, weighing 2.5 kg. Artificial lesions measuring 2 x 7-10 mm were simulated on the cartilaginous plate of the outer ear with a scalpel. 0.5 ml of stem cell suspension (~5 million) obtained from the umbilical cord of rabbits by enzymatic method was injected into the defect site. Histological sections of the cartilage defect were prepared. The samples were stained by Weigert and Azure II methods. The relative density of collagen, elastin fibers, oxyphilic and basophilic tissue elements was programmatically evaluated. Results and discussion: The amount of fibers in the native elastic cartilage was more on 35% of the relative dermis. The newly formed tissues at the damage cartilage was like to the dermis after 2 months. Similar results were found on ear in 2.5 and 3 months after surgery. Native cartilage on histological sections almost was not oxyphilic. Maybe a significant number of acidic components was masked it. Dense connective tissue contains almost equal amounts of both components. Thus, it is possible to trace changes in the intercellular matrix that will characterize the direction of the regeneration process. The area of elastic cartilage defect was characterized by a significant presence of oxyphilic elements after 2 months of the stem cells addition. The ratio of oxyphilic and basophilic components in the native elastic cartilage was about to zero. For the dermis was 1.4-1.5. Dense scar connective tissue was characterized by a ratio about 1. Based on the results obtained, was assumed that the direction of stem cell proliferation is determined shortly after injection. Conclusion: The addition of stem cells to the area of the artificially created elastic cartilage defect of the rabbit's ear was not allow to obtain stable regenerative processes of cartilage tissue and the restoration of the intercellular matrix to its original state. The process of stem cell differentiation contributes the formation of dense connective tissue of the scar, which may be due to the presence of proinflammatory cytokines, growth factors and other biologically active molecules. This was not creating the necessary conditions for the cartilage regeneration.
Purpose: to study the features of the restoration of rabbits outer ear elastic cartilage tissue in the area of the defect after its filling with allogeneic mesenchymal stem cells (MSCs). Materials and methods: Studies were performed on 24 sexually mature rabbits. All animals under general anaesthesia underwent surgery to create a standardized linear defect and were divided into experimental (15 rabbits) and control (9 rabbits) groups. In the experimental group, the defect was filled with suspensions of MSCs in the amount of 5 million cells, and in the control group of cells was not introduced. MSCs were obtained from the umbilical cord of rabbits by the enzymatic method. After the first passage of the MSCs culture, was studied MSCs stem potential and tested ability to differentiating. Material for morphological studies was taken after 1, 2 and 3 months, cryostat sections were prepared hematoxylin-eosin and picrofuxin staining were performed according to van Gizon, as well as morphometry. Results: The introduction of suspensions of allogeneic MSCs in the experiment in the cartilage defect of the outer ear of rabbits causes healing with the activation of pre-existing embryonic cartilage cells, the appearance of cells in a state of division in the adjacent zone, activation of angiogenesis and promotes fibrotization with a predominance of loose connective tissue 1 month after surgery. After 3 months, a more pronounced activation of chondrogenesis is observed with the growth of chondrocytes and their increased number in lacunae, the appearance of isogenic groups of cells, which is combined with vascular activation and the growth of dense scar connective tissue,increased fibroblasts and the number of collagen fibers in the defect area, as well as in the absence of a complete restoration of the characteristic cartilage structure. At that time, in the control group, in the process of defect healing 1 month after the operation, along with the detection of a reduced zone of activation of cartilage chondrocytes and collagen fibers, the development of destructive-dystrophic processes of chondrocytes and the extracellular cartilage matrix was observed. The morphometry data quantitatively confirm a more pronounced activation of chondrogenesis in the areas adjacent to the cartilage defect under the conditions of MSC injection compared to the control. The difference is 20.8% 1 month after the operation and 14.2% 3 months later. The results obtained indicate the promise of using MSCs to activate reparative processes in the area of rabbits outer ear cartilage tissue defect.
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