Photobiomodulation Therapy Affects the Elastic Modulus, Cytoskeletal Rearrangement and Migration Capability of Human Osteosarcoma Cells.

Abstract

Photobiomodulation (PBM) therapy utilizes low-power lasers to modulate the viability of living human cells and leads to changes in proliferation, differentiation, adhesion and gene expression, even though the rearrangement of cytoskeleton was not previously studied. The present study aims to evaluate the photobiological effects on the elastic behavior of human osteosarcoma cells (MG-63) and their morphological changes. Fluorescence staining, confocal imaging and atomic force microscopy (AFM) topography were performed to study the effects of PBM therapy with the exposure of 532nm-25mW, 650nm-3mW, 650nm-150mW and 780nm-70mW beams following the 5-min continuous irradiation. The area of each beam was 3.14cm2 with a source-surface distance of 20cm. Besides the cell proliferation assessment, the migratory potential of MG-63 was determined with the wound healing technique. The results indicated an increase in stiffness and shape index of radiation-induced cells 24h after exposure along with the obvious F-actins changes. But, cell stiffening was not observed 72h after 532nm laser irradiation. Also, a decrease in the migration rate was seen in all of the groups after 72h of irradiation except cells treated with 532nm wavelength. However, 532nm laser beams increase the migratory potential 24h after exposure. Within 72h after irradiation, the cell proliferation was only affected by applying 532nm and 650nm-150mW laser beams. It was concluded that applying photobiomodulation with wavelengths of 650nm (at both utilized powers) and 780nm alters the migration capability and provides a quantitative description of cytoskeletal changes. Moreover, membrane stiffening can be considered as the biological marker of PBM treatments.