Background: To compare the results of the use of mesenchymal stromal cells (MSCs) of human gingival mucosa and MSCs of rat
gingival mucosa, their conditioned media, and to evaluate their effect on tissue regeneration in local radiation injury (LRI).
Material and methods: The study included 120 white male Wistar rats weighing 210 ± 30 g at the age of 8–12 weeks, randomized into 6
groups (20 animals each): control (C), animals did not receive therapy; control with the introduction of culture medium concentrate (CM)
three times for 1, 14, 21 days; administration of human gingival mucosa MSCs (HM) at a dose of 2 million per 1 kg three times for 1, 14, 21
days; administration of human gingival mucosa MSCS conditioned medium concentrate (HMCM) at a calculated dose of 2 million cells per
1 kg three times for 1, 14, 21 days; administration of rat gingival mucosal MSCs (RM) at a dose of 2 million cells per 1 kg three times for 1,
14, 21 days; administration of rat gingival mucosal MSCS (RMCM) conditioned medium concentrate at a calculated dose of 2 million cells
per 1 kg three times for 1, 14, 21 days. Each laboratory animal was observed 17 times: on 1, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91,
98, 105, 112 day after the burn simulation. Histological (hematoxylin-eosin staining) and immunohistochemical (CD31, CD68, VEGF, PGP
9.5, MMP2,9, Collag 1, TIMP 2) studies were performed. LRI was modeled on an X-ray machine at a dose of 110 Gy. MSCs were cultured
according to the standard method up to 3–5 passages, the conditioned medium was taken and concentrated 10 times. The immunophenotype
of MSCs (CD34, CD45, CD90, CD105, CD73, HLA-DR) and viability (7‑ADD) were determined by flow cytofluorimetry.
Results: In a comparative analysis with the control group (C), starting from the 42nd day of the study, a tendency to reduce the area of
skin ulcers in animals in all groups was observed, despite the fact that not all days had statistically significant differences. On day 112th, complete
healing of skin ulcers in the CM group was observed in 40 % of animals in the HM group – in 60 %, in the HMCM group – in 20 %
of animals, in the RMCM group–20 %, and in the C and RM groups there were no animals with a prolonged wound defect.
Positive expression of the VEGF marker was observed in groups C and CM on the 28th day and in experimental groups (HM, HMCM,
RM, RMCM) on the 112th day. A statistically significant increase in the CD68 marker was observed in groups C, RM, and RMCM, while
the remaining groups showed a decrease in the number of macrophages.
HUVECs-conditioned medium has a better potential to stimulate differentiation of dental pulp stromal cells toward an osteoblastic lineage
