Effects of Nd:YAG low-level laser irradiation on cultured human osteoblasts migration and ATP production: in vitro study

Abstract

Low-level laser therapy has become one of the fastest growing fields of medicine in recent years. Many in vivo and in vitro studies have shown that laser irradiation activates a range of cellular processes in a variety of cell types and can promote tissue repair. However, few in vitro experiments have evaluated the effects of laser irradiation on cells in real time. The purpose of this study was to examine the effects of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation on the migration of cultured human osteoblasts. A dedicated 96-well plate was used, and confluent cultures of the human osteoblast-like cell line, Saos-2, were injured with a wound maker. The wounded cells were then exposed to the Nd:YAG laser (wavelength of 1064 nm) for 60 s at 0.3 W (10 pps, 30 mJ). The total energy density was about 10.34 J/cm. Images of the wounds were automatically acquired inside the CO incubator by the IncuCyte ZOOM™ software. In addition, after laser irradiation, the production of adenosine triphosphate (ATP) was measured using the CellTiter-Glo™ Luminescent Cell Viability Assay. Migration of cells from the border of the original scratch zone was accelerated by laser irradiation. In addition, compared with the control group, significant enhancement of ATP production was observed in the irradiated group. The present study showed that Nd:YAG laser irradiation (wavelength of 1064 nm, 0.3 W, 10 pps, 30 mJ, 10.34 J/cm, irradiation time 60 s) may contribute to the regeneration of bone tissues owing to enhanced osteoblast cell migration.

Examination of the Effect of the Combined Use of Nd: YAG Laser Irradiation and Mechanical Force Loading on Bone Metabolism Using Cultured Human Osteoblasts

“…Our previous experiments demonstrated that human-derived osteoblast-like cells irradiated with an Nd: YAG laser were induced to proliferate. 22 In the present study, no proliferation of live cells was observed, potentially because the cells were not damaged by scratches and therefore the response may be different. When combined with the defense responses of the living body, the laser effect may be more likely.…”

Bone marrow coagulated and low‐level laser therapy accelerate bone healing by enhancing angiogenesis, cell proliferation, osteoblast differentiation, and mineralization

“…It can suggest that the process of osteoblastic differentiation was accelerated in this group. It is interesting to note that these findings were distinct from those observed in previous study by Nagata et al, 13 but are supported by other in vivo and in vitro studies which showed that LLLT promotes a significant increase in osteoblastic differentiation 23,50,51 and migration 52 …”

Low-Level Laser Irradiation Modulated Viability of Normal and Tumor Human Lymphocytes In Vitro

“…These changes, in turn, enhance cell proliferation. 17,37,38 It is believed that the mitochondrial cytochrome C oxidase could absorb red to near-infrared light, which is one of the respiratory chain components, resulting in the generation of ROS and adenosine triphosphate (ATP). 38…”