Purpose: To study the regeneration processes in the treatment of radiation skin lesions with the mesenchymal stem cells (MSC) derived from human gingiva and their conditional medium concentrate (CCM) during animal studies. Material and methods: The study includes 80 white male Wistar rats weighing 210 ± 30 g at the age of 8–12 weeks, randomized into 4 groups (20 animals in each): control group (C), animal did not receive treatment; control with the introduction of the conditional medium concentrate (CCM) three times on days 1, 14 and 21; the introduction of MSC in a dose of 2 million cells per 1 kg three times on days 1, 14 and 21; the introduction of CCM in the estimated dose of 2 million cells per 1 kg three times on days 1, 14 and 21. Radiation burn simulation was performed (using on an X-ray unit at a dose of 110 Gy) and each animal was observed 17 times: at days 1, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105 and 112. Histological (stained with hematoxylin-eosin) and immunohistochemical (CD31, CD68, and VEGF) studies were performed. MSC was cultivated according to the standard procedure up to passages 3–5, the conditioned medium was collected and concentrated 10 times. The MSC immunophenotype (CD34, CD45, CD90, CD105, CD73, HLA-DR) and viability (7-ADD) were determined using flow cytometry. Results: Under the assessment of the animal skin on the day 7 in the CCM group, the area was significantly larger compared to the C, MSC, CM groups (р ≤ 0.05). In the CM group on the day 14 the area of the open wound surface and ulcers from day 28 to day 42 was significantly less, compared with the C, MSC and CCM groups (р ≤ 0.05). In group C, from 42 to 77 days of observation, an increase in the area of skin ulcers was observed compared with the CM and CCM groups (р ≤ 0.05). On the day 112, healing of skin ulcers in the CM group was observed in 40 %, in the MSC group in 60 %, and only in 20 % of animals in the CCM group, and in the C group it was not registered. Expression of VEGF marker on endothelial cells and stromal cells was observed in groups C and CM on day 28 and in groups MSCs and CCM on day 112. On the 28th day in the MSC group, the average number of vessels (CD31) in the field of view was 6.0, and on day 112 it was 12.75, р ≤ 0.05, in the CCM group – 19.10 and 28.6, respectively, р ≤ 0.05. An increase in the number of macrophages (CD68) was found in group C from 28 to 112 days (11.6 and 24.73, р ≤ 0.05), and in the CM group the decrease was 22.1 and 13.07, respectively, р ≤ 0.05. Conclusion: Thus, all used treatment modes of radiation skin lesions, including 3-fold administration of CM, MSC and CCM at a dose of 2 million cells per 1 kg, were effective and resulted in a reduction in the damage area, accelerated ulcer healing, and improvement of the regenerative processes. In addition, the use of MSCs led to the improvement of inflammatory processes’ vascularization and reduction in the radiation skin lesions.
Purpose: Study of the effect of paracrine factors, produced by MMSC of bone marrow during the cultivation, on the severity of local radiation injuries in the conditions of application in the early periods after irradiation. Material and methods: Experiments were performed on rats of the breed Wistar weighing 280 g. Rats were exposed locally in iliolumbar region of the back using X-ray machine LNC-268 (RAP 100-10) at a dose of 110 Gy (30 kV tube voltage, current 6.1 mA, filter Al 0.1 mm thick), dose rate is 21.4 Gy/min. Area of the irradiation field was 8.2–8.5 cm2. The conditioned medium obtained by culturing MMSC of rats’ bone marrow was administered in dose 1.0 ml (total protein 8 mg/ml) at 1, 3, 6, 8 and 10 days after irradiation. The severity of radiation damage to the skin and the effects of therapy were evaluated in dynamics by clinical manifestations, using planimetry and histological methods. Results: It was shown that in control animals and in rats, with the introduction of the conditioned medium, the values of the skin lesion area in the period up to the 29th day after irradiation practically did not differ, gradually decreasing in control animals from 5.9 ± 0.6 cm2 to 2.2 ± 0.3 cm2 at the 15th and 29th days after irradiation, respectively. Then, in the control group, the lesion area ranged from 1.4 ± 0.6 cm2 on the 50th day to 1.9 ± 0.8 cm2 on the 71st day. In the experimental group of animals, with the introduction of factors of the conditioning medium, a decrease in the area of the lesion and a stable dynamics of healing of radiation ulcers, beginning from the 36th day, there was a gradual decrease in the area of the lesion, which reached 0.2 ± 0.1 cm2 by the 71st day after irradiation. On the 64–71th day after irradiation, the difference between the areas of skin lesion in the experimental and control groups was statistically significant, p <0.05. The histological analysis showed that the use of paracrine factors obtained from MMSC in the process of cultivation significantly reduces the severity of the inflammatory reaction and accelerates the regeneration processes. Conclusion: Thus, the introduction of conditioned medium factors obtained during the cultivation of mesenchymal stem cells of the bone marrow facilitates a more easy flow of the pathological process and the healing of radiation ulcers after local radiation damage to the skin of rats. Apparently, the favorable effect of paracrine factors introduced in the early periods after irradiation, with severe local radiation injuries, is associated with their effect on pathological processes in the inflammatory-destructive stage.
Medical examinations for employees of organizations using sources of ionizing radiation, have a number of features, including the need for a «specialized» medical examination with mandatory psychophysiological examination.
Purpose: To study the effect of radiation sterilization at an ultra-high dose of 30 kGy on the cytocompatibility of decellularized vascular scaffolds repopulated with placenta MSCs. Materials and methods: The material of the study were aortas of laboratory animals (rabbits and rats, three vessels for each animal species), which were subjected to detergent - enzymatic perfusion decellularization by two protocols differing in reagents composition. Then the scaffold decellularized by the most efficient protocol was irradiated at a dose of 30 kGy and repopulated with placenta MSCs. As a control, the unirradiated matrix was seeded with cells of the same type. Histological staining of hematoxilin – eosin, IHC for type I collagen and Ki67, DAPI staining and quantitative assessment of genomic DNA were used to evaluate the effectiveness of decellularization and seeding. Scaffolds seeding was assessed by analyzing serial sections taken on day 1st, 3rd, and 4th of culture. Results: The scaffolds obtained in accordance with Protocol 1 were characterized by the absence of detectable cell nuclei, while the DNA content in them was significantly lower compared to Protocol 2. On the digitized images of sections of the unirradiated matrix, the cell nuclei were determined for routine H&E and DAPI staining while for the irradiated scaffold the cell nuclei were visualized on the border between the scaffold and fibrin gel only on DAPI stained section at 1st day of culture. The frequency of occurrence of Ki67+ nuclei on the 4th day of culture was significantly lower for the irradiated scaffold in comparison with the non-irradiated scaffold (7.5% and 29.8%, respectively, p=0.0054). Conclusion: Scaffold irradiation leads to loss of cytocompatibility of tissue-engineering constructs.
Aim.To develop a safe protocol for cryopreservation of segments of iliac arteries straight after their retrieval from post-mortem donor with the use of polydimethylsiloxane as a coolant and cryoprotectant.Materials and methods.Eleven segments of iliac arteries were retrieved from post-mortem donor and divided into four groups including control. Based on preliminary heat and cold transfer mathematical modeling and tests with tissueequivalent phantom arterial segments were placed on plastic mounts and cryopreserved by following protocol: groups 1 and 2 were immersed in polydimethylsiloxane and cooled rapidly at 180 °С/min to –75 °С. Group 3 segments were cryopreserved at 1,6 °С/min in PDMS – fi lled cryo-container placed in the freezer at –80 °С. All segments were defrosted by immersion in PDMS at +24 °С and then examined for morphology changes by histological methods and SEM. EDS analysis with the use of AzTech software also was performed for Si – content evaluation. Restricted biomechanical tests were conducted for group 2 segments.Results.There were no signifi cant morphological differences between segments of the control and cryopreserved groups except for the segment with slow cooling.Conclusion.Mobile cryopreservation may allow increasing the effi ciency of retrieval of a large number of donor tissues for possible later use in the processing of bioprostheses of blood vessels; or, after decellularization, as well as tissue-specifi c matrices for tissue-engineering blood vessels.
Purpose: To investigate the effectiveness of autologous cells of stromal vascular fraction of adipose tissue in severe local radiation skin injuries after the exposure of rats to X-rays. Material and methods: Experiments were performed on Wistar rats, weighing 200–230 g. Rats were exposed locally in iliolumbar region using X-ray machine LNC-268 (RAP 100-10) at a dose of 110 Gy (30 kV tube voltage, current 6.1 mA, thick Al filter 0.1 mm), dose rate: 17.34 Gy/min. Area of the irradiation field was 8.2–8.5 cm2. Transplantation of autologous cells of stromal vascular fraction (SVFC) of adipose tissue was carried out on 21st or 35th days after irradiation. SVFC isolation was performed by means of enzymatic treatment of adipose tissue. SVFC suspension was administered subcutaneously at a dose of 1×106 cells per injection around the radiation ulcers.The severity of radiation damage to the skin and the effects of cellular therapy were evaluated in the dynamics of clinical manifestations, with the help of plane geometry and pathomorphometry. Results: It was found that by the 17–25th day after irradiation radiation ulcers were formedon rat skin. In the control group of animalsulcers persisted throughout the observation period of more than 3 months. The area of ulcers was 1,87 ± 0,35 cm2 and 1.52 ± 0.24 cm2 at 83th and 90th days after irradiation, respectively. In animals of the experimental group, with autologous stromal vascular fraction of adipose tissue, was significant decrease in ulceration the area in comparison to control animals. In 80 % of the rats treated with SVFC on 21st day after exposure, to the 90th day after irradiation complete healing of ulcers occurred with the formation of atrophic scar at the site of radiation injuries. These clinical observations and planimetric were correlated with the results of histomorphometry. Conclusion: Transplantation autologous SVFC of adipose tissue contributes to accelerate the healing of radiation ulcers after local x-ray exposure in the experiment, indicating that the prospects of using adipose tissue cell products for the treatment of severe local radiation injuries.
Treatment of local radiation injuries (LRI) is one of challenges of radiation medicine, at the same time tactics and strategy of therapy of these pathologies remain up to the extremity not developed. Recently the increasing place in a clinical practice is borrowed with various methods of cellular and tissue therapy. The certain successes in development and clinical application of the various biomaterials stimulating reparative processes and replacing defects of a skin are reached. The epidermis is one of the important functional units of a skin as organ, and its ability to self-renewal is defined by presence stem cells (Terskih V.V. et al., 2001). As a result of damage which can wear chemical, mechanical, thermal or radiative character, the structure of a epidermis and a derma varies, structurally functional units disappear, and keratinocytes and fibroblasts get a new phenotype. However, not looking at huge quantity of works of the proliferative abilities devoted to studying keratinocytes and fibroblasts and as to their use with the purpose of replaceable therapy at influence of various injuries factors, experience of clinical application of these technologies at patients with LRI for today is absent. We for the first time used a method of replacement of defect of a skin with use autological keratinocytes and fibroblasts at the patient with LRI. With the purpose of application of cellular technologies to the patient the intraoperative biopsy of a healthy dermal graft is made. In the further it was carried out growth autological keratinocytes and fibroblasts. Creation of a design includes 4 stages: a biopsy of a donor material; growth cells in vitro; creation tissue engineering designs; transplantation tissue engineering designs in area of injury. Use of cell technologies alongside with traditional surgical and therapeutic methods of treatment LRI shows high efficiency and perspectivity of this direction. Thus, studying of specificity of radiative influences on cells of a skin and as use autologic keratinocytes and fibroblasts in the program of treatment of patients with local radiation injuries for replacement of defects, represents appreciable scientific and practical interest, and their application with the purpose of optimization of current reparative processes has a pathogenetic substantiation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.