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.
TISSUE IMMUNE CELLS AND THEIR ROLE IN THE HEALING PROCESS OF INFECTED RADIATION ULCERS UNDER THE IMPACT OF PHOTODYNAMIC THERAPY (EXPERIMENTAL STUDY)