Application of Regenerative Cell Technologies in the Treatment of Severe Local Radiation Injuries in Victims of Emergency Situations: from the Experience of the Specialists of the Federal Medical Biophysical Center Named after A.I. Burnazyan of the Federal Medical and Biological Agency of Russia

It has been noted that one of the most common types of radiation injuries when a person is exposed to ionizing radiation is radiation burns — severe local radiation injuries. The aim of the study is to apply stromal and vascular fraction of adipose tissue to increase the efficiency of complex therapy for local radiation lesions. Materials and methods of the study. In 2017-2019, 7 patients (all male; mean age — (54.83±9.41) years) with local radiation lesions of the skin — ulcerative-necrotic lesions of the skin and underlying tissues — were treated at the Federal Medical Biophysical Center named after A.I. Burnazyan of FMBA of Russia. For more than 6 months the patients received conventional conservative therapy of local radiation lesions and a single injection of cell suspension of autologous cells of stromal-vascular fraction of adipose tissue — the average number of cells was (60.33×106±64.04). Results of the study and their analysis. All patients had no serious adverse events and reactions associated with the introduction of autologous regenerative cells of adipose tissue. During the whole period of observation after stromal-vascular fraction of adipose tissue was injected, late radiation ulcers remained without signs of inflammation and infiltration. The patients were discharged from the hospital in satisfactory condition. According to the authors, the use of stromal-vascular fraction of adipose tissue in local radiation lesions provides favorable conditions: to increase the effectiveness of complex therapy; to reduce healing time of the wound surface; to regulate and activate immune and reparative processes in the dermis; to restore the damaged vascular network, lost skin without severe scarring changes; to heal and achieve a satisfactory result, decent quality of life of patients.

The Influence of Mesenchymal Stem Cells of Adipose Tissue and Paracrine Factors of Conditioned Medium on the Healing of Radiation Ulcers in the Treatment of Severe Radiation Injuries of Skin in Rats

Purpose: Studying of the effects transplantation of cultured mesenchymal stem cells of adipose tissue (MMSC) and adipose-derived stromal vascular fraction (SVF), as well as the introduction of paracrine factors (PF) of conditioned medium in an isolated or combined application for severe local radiation skin lesions in the experiment. Material and methods: Rats of the inbred Wistar–Kyoto strain were irradiated to local X-rays exposure in the iliolumbar region of the back at a dose of 110 Gy. The transplantation of cultured MMSC was performed twice at doses of 2.1 × 106 and 2.6 × 106 on the 28th and 35th days after irradiation. Adipose-derived SVF was administered at the same time in doses of 3.2 × 106 and 2.8 × 106, respectively. PF were administered five times from the 1st to the 10th day 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: Radiation exposure with these parameters caused severe radiation injuries of the skin with non-healing ulcers formed by the 21–25th day after irradiation. The area of radiation ulcers in rats of the control group in the period from the 26th to the 83rd day slowly decreased from 2.76 ± 0.12 cm2 to 1.85 ± 0.13 cm2. In 50 % of the animals in the control group, ulcers persisted for more than 4 months after irradiation. In rats of the experimental groups, more intensive healing and a decrease in the area of radiation ulcers was noted. With isolated administration of cultured MMSC or SVF, a statistically significant decrease in the area of ulcers compared with the control was observed on the 104–125th day, and with the introduction of PF on the 83rd day after irradiation, p <0.05. In the control group, by the118th day after irradiation, radiation ulcers healed only in 25 % of rats, and in the experimental groups with isolated administration of cultured MMSC, SVF and PF in 40–55 % of the rats showed complete epithelialization of wounds with the formation of an atrophic scar. Under the conditions of combined use of stem cells and conditioned medium factors, the number of animals with complete healing of radiation ulcers was 85–100 % by 118th days, p <0.05. Conclusion: Thus, transplantation of cultured MMSC of adipose tissue and adipose-derived SVF, as well as the introduction of PF of conditioned medium, can enhance the regeneration processes and stimulate skin regeneration, promoting earlier healing of chronic radiation ulcers in severe local radiation injuries. Moreover, with the combined introduction of PF and adipose-derived stem cell transplantation, the effectiveness of the healing of radiation ulcers was increases.

Evaluation of immediate and long-term results of treatment of post-radiation injuries of the rectum

Introduction. Treatment of post-radiation damage to the rectum is a complex medical problem. The search for new methods of treatment for this category of patients based on modern achievements in regenerative surgery is urgent.The aim of the study was to evaluate the immediate and long-term results of treatment of post-radiation lesions of the rectum using microfat grafting.Materials and methods. The study involved 66 patients — women aged 28 to 83 years inclusive with complications of radiation therapy (rectovaginal fistulas, radiation proctitis, radiation ulcers).Results and discussion. After the treatment, there is a tendency to improve the condition. So, if before the procedure the average sizes of fistulas and ulcers were 1.67 ± 0.54 cm in diameter, then after 3 months these indicators were 1.39 ± 0.54, and after 6 months — 1.1 ± 0.56 cm Complete epithelialization of the defect was observed in all patients. The period for which it was possible to achieve complete epithelialization varies from 6 months to 2 years. On average, to achieve complete epithelialization of post-radiation damage to the rectum, most patients required 3 injections of autologous adipose tissue. Also, all patients showed an improvement in elastometry indices over time. As a result of treatment, there is a tendency to improve the quality of life of patients.Conclutions. The study allows us to conclude about the effectiveness of the treatment, as well as that in the long term, the treatment will also be effective, the likelihood of relapse is minimal.

Late complication of the oral cavity and oropharynx after interstitial neutron therapy with sources of Cf-252

Radiotherapy is used to treat approximately 80% of patients with cancer of the head and neck. Despite enormous advances in radiotherapy planning and delivery, a significant number of pa-tients will experience radiation-associated toxicities. Many effective management options are available for acute radiotherapy-associated toxicities, but treatment options are much more lim-ited and of variable benefit among patients who develop late sequelae after radiotherapy. The present work is based on observations of 586 patients with oral and oropharynx cancer, for which interstitial neutron therapy was carried out in an independent version or in combination with re-mote radiation therapy. Radiation injuries occurred in 130 (22.2%) patients, in 92 (15.7%) they appeared in the form of radiation ulcers and in 38 (6.4%) – osteoradionecrosis of the lower jaw. The clinical picture and the course of radiation injuries after interstitial neutron therapy with sources of 252Cf did not differ significantly from radiation complications after photon irradiation.

Radiation ulcer treatment with hyperbaric oxygen therapy and haemoglobin spray: case report and literature review

Objective: To explore the effectiveness of a combination of hyperbaric oxygen therapy and haemoglobin spray in radiation ulcer treatment. Method: We reviewed the available literature and present a case report in which radiation ulcer was treated with a combination of hyperbaric oxygen therapy and haemoglobin spray. Results: After 30 sessions of hyperbaric oxygen therapy (2.4 ATA; 90 minutes each session) and administration of haemoglobin spray, the wounds showed gradual progress towards healing and a good granulating base was achieved. The wounds were closed after two months using a small split thickness skin graft. Conclusion: A combination of hyperbaric oxygen therapy and haemoglobin spray was effective as a short course of treatment for radiation ulcers.

THE EFFECT OF PHOTODYNAMIC THERAPY AND PLATELET-ENRICHED PLASMA ON THE HEALING OF SKIN RADIATION ULCERS INFECTED BY STAPHYLOCOCCUS AUREUS

Objective. To determine in experiment the quality of healing of skin radiation ulcers infected with Staphylococcus aureus (S. aureus) under the photodynamic therapy (PDT) administration and the use of platelet-rich plasma (PRP). Materials and methods. The experiment was performed on 95 male WAG rats of 6 months of age, which were divided into three groups. Group 1 included animals in whom a skin radiation ulcers in the thigh area was simulated, followed by application of a 0.2 ml suspension of reference strain of S. aureus to its surface on the 7th day after irradiation. Group 2 included animals with S. aureus-infected skin radiation ulcers, in whom the PET was administered a day after infection contamination. Group 3 included animals with S. aureus-infected skin radiation ulcers, in whom the PDT was administered a day after infection in the morning, and the PRP was manifold injected in periwound area in the afternoon. The skin with underlying soft tissues from the area of radiation damage were the material for morphological examination. The hematoxylin and eosin, picrofuxin according to van Gizon, Mallory staining were applied to micropreparations. A morphometric study was conducted. Results. In animals with skin radiation ulcers, in whom the PDT was administered upon infection with S. aureus (group 2), compared with animals with simulated infected skin radiation ulcers without treatment (group 1), The activation (i.e. accelerating) of the healing occurred for the period from the 14th to the 52nd day of experiment due to the active processes of wound cleansing from necrotized tissues, less pronounced inflammatory changes in the lesion, and active of appearance and maturation of granulation tissue, less pronounced hemodynamic, ischemic and alternative disorders in the dermis, hypodermis, muscle tissue surrounding the wound cavity, activation of proliferative processes in epithelial layer localized in the marginal parts of the wound. Formation of pathological (hypertrophic or keloid) scar of the skin was the result of healing of skin radiation ulcer infected with S. aureus. In animals with radiation ulcers infected with S. aureus, in the case of PDT and PRP (group 3) the regenerative process was directed not only at accelerating the rate of healing, but also on restoration of original structure of the lost parts of the skin compared with only PDT administration (group 2). Acceleration of the healing of the infected skin radiation ulcer in animals of groups 2 and 3 was due to similar processes. Conclusions. Photodynamic therapy activates and accelerates the healing process of skin radiation ulcers infected with S. aureus and leads to formation of a pathological scar (hypertrophic or keloid). Healing of the infected S. aureus radiation ulcers occurs more actively upon the photodynamic therapy administration in combination with multiple periwound injections of the platelet-enriched plasma, compared with only photodynamic therapy administration, and finishes with an organotypic regeneration and almost complete skin recovery. Key words: photodynamic therapy, platelet-rich plasma, radiation skin ulcer, Staphylococcus aureus, morphology.

Cellular senescence is a promising target for chronic wounds: a comprehensive review

Chronic wounds include, but are not limited to, radiation ulcers, pressure ulcers, vascular ulcers and diabetic foot ulcers. These chronic wounds can persist for years without healing and severe ulcers may lead to amputation. Unfortunately, the underlying pathologies of refractory chronic wounds are not fully characterized, and new treatments are urgently needed. Recently, increasing evidence has indicated that cell senescence plays an important role in the development of chronic wounds, and preventing cell senescence or removing senescent cells holds promise as a new therapeutic strategy. In this review, we aim to probe these latest findings to promote the understanding of cellular senescence in the pathological process and potential management of chronic wounds.

Study of the effects of stromal vascular fraction, cultured adipose-derived stem cells, and paracrine factors of a conditioned medium in the treatment of severe radiation injuries of rat skin

Цель - изучение влияния трансплантации стромально-васкулярной фракции (СВФ), культивированных мультипотентных мезенхимальных стволовых клеток (ММСК) жировой ткани и введения паракринных факторов кондиционной среды, полученных при культивировании ММСК, на течение тяжелых местных радиационных поражений кожи. Методика. Крыс инбредной линии Wistar-Kyoto облучали на рентгеновской установке в дозе 110 Гр, при мощности дозы 20,0 Гр/мин. Напряжение на трубке 30 кВ, ток 6,1 мА, фильтр Al толщиной 0,1 мм, площадь поля облучения составляла 8,5 см2. Трансплантацию клеток СВФ жировой ткани проводили двукратно в дозах 2,2 х 106 и 3,0 х 106 на 28-е и 35-е сут после облучения, соответственно. Культивированные ММСК вводили в дозах 2,8 × 106 и 3,4 × 106 на 28-е и 35-е сут после действия радиации. Паракринные факторы кондиционной среды вводили пятикратно с 1-х по 10-е сут после облучения, подкожно по 1,0 мл (общий белок 8 мг/мл). Тяжесть лучевого поражения кожи и эффекты терапии оценивали в динамике по клиническим проявлениям, с помощью планиметрии и патоморфологических методов. Результаты. Выбранный режим радиационного воздействия вызывал тяжелые лучевые поражения кожи с длительно (до 5 мес) незаживающими язвами. Площадь лучевых язв у крыс контрольной группы в период с 28-х до 84-х сут медленно уменьшалась от 2,73±0,17 см2 до 1,52±0,17 см2, а через 4 и 5 мес после облучения составляла 0,52±0,15 см2 и 0,05±0,04 см2, соответственно. Во всех опытных группах после 84-х сут отмечалась тенденция к снижению площади лучевых язв, а через 4 мес после облучения уменьшение площади язв и снижение тяжести поражения в опытных группах по сравнению с контролем были статистически значимыми (р < 0,05). У 70-80 % крыс в опытных группах через 4 мес после облучения наблюдалась полная эпителизация радиационных ран с образованием атрофического рубца, а в контрольной группе в этот период атрофические рубцы наблюдались лишь у 40% крыс. Заключение. Трансплантация СВФ жировой ткани или культивированных ММСК, а также введение паракринных факторов кондиционной среды способствуют усилению регенераторных процессов в пораженной ткани, и могут быть в равной степени эффективны при терапии тяжелых лучевых поражений кожи в эксперименте. Aim. To study effects of stromal-vascular fraction (SVF) transplantation, cultured multipotent mesenchymal stem cells (MMSC) of adipose tissue, and administration of paracrine factors of the conditioned MMSC culture medium on the course of severe, local radiation lesions of the skin. Methods. Wistar-Kyoto rats were irradiated with X-rays at a dose of 110 Gy and a dose rate of 20.0 Gy/min. The tube voltage was 30 kV, current - 6.1 mA, filter -0.1 mm thick A1, and irradiation field area - 8.5 cm2. Transplantation of adipose tissue SVF cells was performed twice at doses of 2.2 x 106 and 3.0 x 106 on the 28th and 35th days after irradiation, respectively. Cultured MMSC was administered at doses of 2.8 x 106 and 3,4 x 106 on the 28th and 35th days after irradiation. Paracrine factors of the conditioned medium were administered five times from the 1st to the 10th day after irradiation at a dose of 1.0 ml, s.c. (total protein, 8 mg/ml). Severity of radiation damage of the skin and effects of the therapy were followed up by clinical manifestations using planar geometry and pathomorphological methods. Results. Radiation exposure under the specified conditions caused severe radiation injuries of the skin with nonhealing ulcers that persisted for up to 5 months after irradiation. In control rats the area of radiation ulcers slowly decreased between the 28th and 84th days from 2.73 ± 0.17 cm2 to 1.52 ± 0.17 cm2, respectively, and was 0.52 ± 0.15 cm2 and 0.05 ± 0.04 cm2 at 4 and 5 months after irradiation. In all experimental groups, the healing was more intensive after the 84th day with a tendency to decrease the area of radiation ulcers; at 4 months after irradiation, statistically significant decreases in the area of ulcers and severity of lesions were observed in the experimental groups compared to the control (p <0.05). At four months after irradiation, 70-80% of rats in the treatment groups showed complete epithelialization of radiation wounds with formation of an atrophic scar whereas in the control group during the same period, atrophic scars were observed only in 40% of rats. Conclusion. Transplantation of adipose-derived SVF or cultured adipose tissue MMSC as well as administration of paracrine factors of the conditioned medium contributed to the enhancement of regenerative processes in the affected tissue and can be equally effective in the treatment of severe experimental radiation lesions of the skin.