Combined Use of Surgical Excision of Radiation Ulcers and Transplantation Syngeneic Cells of the Stromal-Vascular Fraction of Adipose Tissue in the Treatmentof Severe Local Radiation Lesions in the Experiments
Authors:   A.I. Burnasyan Federal Medical Biophysical Center, Moscow, Russia, Deshevoi Yu. B. , Lebedev V. G. ,   A.I. Burnasyan Federal Medical Biophysical Center, Moscow, Russia, Nasonova T.A. ,   A.I. Burnasyan Federal Medical Biophysical Center, Moscow, Russia, Dobrynina O.A. ,   A.I. Burnasyan Federal Medical Biophysical Center, Moscow, Russia, Lyrshhikova A.V. ,   A.I. Burnasyan Federal Medical Biophysical Center, Moscow, Russia, Astrelina T.A. ,   A.I. Burnasyan Federal Medical Biophysical Center, Moscow, Russia, Moroz B.B. ,   A.I. Burnasyan Federal Medical Biophysical Center, Moscow, Russia
Published: April 2022

Purpose: To study the therapeutic efficacy of the combined use of surgical excision of radiation ulcers and transplantation of syngeneic cells of the stromal-vascular fraction (SVF) of adipose tissue in the treatment of severe local radiation lesions. Material and methods: Experiments were conducted on rats males of the inbred line Wista‒Kyoto weighing 230‒250 g. Animals were irradiated on an X-ray unit locally in the iliac-lumbar region of the back at a dose of 110 Gy (voltage on the tube 30 kV, current strength 6.1 mA, filter 0.1 mm Al), at a dose rate of 20,0 Gy/min. Irradiation field area 8.2 cm2. Radiation exposure made it possible to obtain severe skin lesions in rats with long-term non-healing ulcers, and without critical radiation exposure to the underlying tissues. Morphological study showed that the area of skin necrosis (with a maximum in the center of the irradiation zone) was formed by 21‒23 days after irradiation and was characterized by the presence of pronounced changes in all layers of the skin. Surgical excision of radiation ulcers was performed on 22 days after exposure to radiation. The affected tissue was removed to the entire depth of the skin up to the fascia of skeletal muscles. Excision of the skin was carried out, retreating 6‒8 mm from the outer border of the radiation ulcer. Cell transplantation was carried out twice 5 and 12 days after excision of the ulcer. SVF cells were obtained from intact animals from subcutaneous adipose tissue treated with trypsin. A suspension of SVF cells of adipose tissue in 1 ml of a sterile Solution of Henks was injected under the skin at 5 points around the excision zone, retreating 5‒7 mm from the edge of the focus. The number of injected cells in one transplant was 2.5×106. Results: The area of radiation ulcers in rats of the control group in the period from 27 to 105 days after irradiation slowly decreased from 2.8±0.2 cm2 to 1.2 ± 0.2 cm2. Excision of radiation ulcers led to rapid complete visible healing of the wound defect (already by 70 days after irradiation) with the formation of atrophic scars. Transplantation of SVF syngeneic cells increased the rate of healing of the surgical wound. Conclusion: The results show that surgical excision of radiation ulcers in combination with cell therapy may be an effective way to treat severe local radiation lesions.