Study of the Efficacy of Cell Therapy for Severe Local Radiation Injuries in the Use of Drugs Affecting the State of Irradiated Tissues Before Cell Transplantation

Purpose: To study the possibility of enhancing the therapeutic efficacy of multipotent mesenchymal stromal cells (MMSC) or stromal vascular fraction (SVF) cells in the treatment of severe local radiation injuries under the conditions of the use of pharmacological drugs, the use of which before and after cell transplantation can improve the condition of the irradiated tissue and thereby create favorable conditions for engraftment and functioning of the injected cells.

Material and methods: The work was carried out on male rats of the Wistar–Kyoto inbred line weighing 260–280 g. The animals were locally irradiated in the iliolumbar region of the back on an X-ray machine LNK-268 (RAP 100–10) at a dose of 110 Gy (voltage on the tube 30 kV, current 6.1 mA, Al filter with a thickness of 0.1 mm), at a dose rate of 20.0 Gy/min. The area of the irradiation field was 8.5 cm². The severity of radiation damage to the skin and the effects of treatment were assessed in dynamics by clinical manifestations and using planimetry. After exposure to radiation, rats developed radiation ulcers of the skin that did not heal for a long time (up to 3–4 months). Cell and drug therapy were carried out in different periods after irradiation: from the 28th to the 49th or from the 35th to the 56th day. As drugs affecting the condition of the affected tissues surrounding the formed radiation ulcer, a complex antibiotic levotetrasulfin forte and drugs that affect the microcirculation and trophism of irradiated tissues – pentoxifylline and detralex were used. For cell therapy, syngeneous MMSC or SVF cells were used. In the cell therapy setting, the drugs were administered for one week before the first cell transplant, one week between the first and second transplantation, and one week after the second cell transplant.

Results and Conclusion: It was shown that the administration of drugs or the use of cell therapy when used separately stimulated the healing of radiation ulcers. Moreover, the therapeutic effect of cell therapy is more pronounced than with the use of drugs. However, in combination with drug and cell therapy, no enhancing effect of pharmacological agents on the therapeutic efficacy of transplantation of MMSC or SVF cells of adipose tissue was noted. Thus, these experiments showed the possibility of successful use of a complex antibiotic in combination with drugs that improve blood supply and trophism of irradiated tissues in the treatment of severe local radiation injuries and the inability of drug therapy under these conditions to enhance the therapeutic effectiveness of cell therapy.