Photobiomodulation Therapy in the Proliferation and Differentiation of Human Umbilical Cord Mesenchymal Stem Cells: An In Vitro Study

Abstract Introduction: Since photobiomodulation therapy (PBMT) favors in vitro mesenchymal stem cell (MSC) preconditioning before MSC transplantation, increasing the proliferation of these cells without molecular injuries by conserving their characteristics, in the present in vitro study we analyzed the effect of PBMT on the proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs).Methods: Irradiation with an InGaAIP Laser (۶۶۰ nm, ۱۰ mW, ۲.۵ J/cm۲, ۰.۰۸ cm۲ spot size, and ۱۰ s) was carried out. The cells were divided into four groups: CONTROL [cells grown in Dulbecco’s Modified Eagle Medium (DMEM)], OSTEO (cells grown in an osteogenic medium); PBMT (cells grown in DMEM+PBMT), and OSTEO+PBMT (cells grown in an osteogenic medium-plus PBMT). The cell proliferation curve was obtained over periods of ۲۴, ۴۸ and ۷۲ hours using the ۳-(۴,۵-dimethyl-۲-thiazolyl)-۲,۵-diphenyl-۲H-tetrazolium bromide (MTT) assay. Osteogenic differentiation was analyzed by the formation of calcium nodules over periods of ۷, ۱۴ and ۲۱ days. Morphometric analysis was performed to quantify the total area of nodular calcification.Results: The highest cell proliferation and cell differentiation occurred in the OSTEO+PBMT group, followed by the PBMT, OSTEO, and CONTROL groups respectively, at the observed times (P < ۰.۰۵).Conclusion: PBMT enhanced the osteogenic proliferation and the differentiation of hUCMSCs during the periods tested, without causing damage to the cells and preserving their specific characteristics, a fact that may represent an innovative pretreatment in the application of stem cells. Keywords: Photobiomodulation Lasers Stem cells Cell differentiation