The effect of low-level laser therapy on growth rate and proliferation of mouse embryonic fibroblasts and evaluation of gene expression changes in growth and inflammatory factors involved in wounds healing

Background and Aim: Pressure ulcers (bed sores) affect many patients around the world and impose huge costs on patients and health services of the country every year. Common treatments such as ointment, serum, dressing and surgery are not fully responsive to such ulcers. One of the new therapies with high potential is laser therapy. Laser light has many uses depending on the wavelength and energy density and the type of target tissue or cell. The most commonly used laser treatment for skin lesions is red light (wavelength range is ۶۲۰ - ۷۷۰ nm) however, several have reported the positive effects of green light (wavelength range is ۴۷۰ -۵۵۰ nm) and blue light (wavelength range of ۴۰۰ to ۴۸۰ nm) to heal skin lesions. Objective: To evaluate different doses (different energy densities) of ۴۵۰ nm blue laser light on mouse embryonic fibroblast cells and to find the appropriate laser dose to enhance the viability and growth rate of fibroblast cells as one of the most important cells involved. In the process of wound healing and evaluation of expression of growth factor genes (VEGF, TGF-b) and inflammatory factor (IL-۶, TNF-a).Methods: Fibroblast cell culture. Cell count and implantation of cells in ۹۶-well plates for mtt assay. ۴۸-hour treatment of cells with different doses of blue light. Perform mtt assay. Data analysis with Graph pad software. Cell culture in Petri dish with ۳.۵ cm diameter to test real time pcr. Treatment of cells with the optimum dose obtained from mtt. Extraction of RNA. C-DNA synthesis. Design primer. Real time pcr. Normalization of data with GAPDH reference gene. Graph drawing with Graph pad software Results: blue light laser (wavelength ۴۵۰ nm) at ۶ cm distance from cells with ۷۵ mW power and energy density of ۰.۶۳ and ۰.۹۵ j/cm۲, significantly increased growth and proliferation compared to the control group. also under optimum doses, two growth factors (vegf, TGF-b) showed a significant increase and two inflammatory factors (IL-۶, TNF-a) showed a significant decrease.Conclusion: Based on the above results it can be suggested that low level laser blue light at low doses (less than ۰.۹۵ joule / cm۲) can increase the survival and growth and proliferation rate of fibroblast cells. Increase the expression of growth factors and decrease the expression of inflammatory factors and shorten the phase of inflammation. In the next steps, this test can then be performed on animal models and ultimately on humans and used as a single treatment approach or in combination with other therapies.

کلیدواژه ها:

Pressure ulcers (bed sores) ، low-level laser therapy ، blue light ،