The effect of photobiomodulation therapy on the expression of regulatory molecules in chronic wound healing

Aim: The work aimed to study the effect of photobiomodulation (PBM) therapy on the expression of key regulatory interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-4 (IL-4), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and granulocyte-macrophage colony-stimulating factor (GM-CSF), influencing the development of reparative processes of chronic wounds.

Materials and Methods: The experiment involved 3 groups of rats: intact animals and animals of the control and experimental groups, for which chronic wounds were simulated. Exposure to wound defects of animals of the experimental group was carried out using PBM therapy. Animals were euthanized on the 14th and 28th day of the experiment. The levels of IL-1β, IL-6, IL-4, IL-10, TNF-α, and GM-CSF in the blood serum of animals were studied by enzyme immunoassay. Histological studies were carried out. The semi-quantitative method was used to evaluate the reepithelization stage, polymorphonuclear leucocytes, fibroblasts, new vessels, and new collagen.

Results: In our work in a group of animals using PBM therapy, the levels of IL-1β, IL-6, TNF-α, GM-CSF, and IL-10 did not change during the proliferationto-remodeling transition phase. The application of PBM therapy resulted in an increase in IL-4 on day 14 of the experiment. The semi-quantitative method demonstrated a change in the number of histologic processes and structures after using PBM therapy.

Conclusions: An imbalance in the production of pro-inflammatory cytokines was found with the use of PBM therapy in our study. An increase in the levels of anti-inflammatory cytokines, the number of fibroblasts, and collagen after laser treatment was shown.