Effects of Low-Level Laser Therapy on Reactive Oxygen Species, Platelet Aggregation Activity, and the Expression of Growth Factors in the Process of Regeneration of Chronic Wounds

Abstract

An understanding of the cellular and molecular mechanisms underlying wound healing with photobiomodulation (PMB) therapy will allow the influence on repair processes, which will lead to new and effective therapeutic strategies for many pathological conditions. The aim of our work was to study the effect of PBM therapy on the regulation of reparative processes in chronic wounds. Studies were performed on 30 Wistar rats. Rats were used for modeling a chronic wound. Animals were divided into two groups: control and experimental. The animal wounds from the experimental group were treated with low-intensity laser radiation in continuous mode using a wavelength of 660 nm, an output power of 50 mW, an energy density of 1 J/cm², and 60 s exposure time. The animals were removed from the experiment on the 3^rd and 7^th days, with 6 animals from each group. The study of the levels of reactive oxygen species (ROS), platelet-derived growth factor (PDGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and basic fibroblast growth factor (bFGF) was carried out. Induced platelet aggregation was studied. Changes in the expression of the studied parameters in the blood serum of animals with chronic wounds when using PBM therapy were found: a decrease in ROS levels and an increase in bFGF concentrations at the initial stages of wound healing. The multidirectional effect of PBM therapy on GM-CSF and PDGF levels was observed in the studied time frame. The use of PBM therapy makes it possible to regulate disturbances in reparative processes by modulating ROS, platelet aggregation activity, and the expression of endogenous growth factors.