Investigation of photobiomodulation potentiality by 635 and 809 nm lasers on human osteoblasts

Abstract

Photobiomodulation (PBM) describes light-induced photochemical reactions achieved by the application of red or near infrared lasers/LED light with low energy densities. This noninvasive and painless method has been used in some clinical areas but controversial outcomes demand a skeptical look for its promising and potential effects. In this detailed in vitro study, the osteoblast cells were irradiated with 635 and 809 nm diode lasers at energy densities of 0.5, 1, and 2 J/cm. Cell viability, proliferation, bone formation, and osteoblast differentiation were evaluated by methylthiazole tetrazolium (MTT) assay, Alamar Blue assay, acridine orange/propidium iodide staining, alkaline phosphatase (ALP) activity, Alizarin red staining, and reverse-transcription polymerase chain reaction (RT-PCR) to test the expression of collagen type I, ALPL, and osteocalcin. The results indicate that studied energy doses have a transient effect (48 h after laser irradiation) on the osteoblast viability and proliferation. Similarly, laser irradiation did not appear to have any effect on ALP activity. These results were confirmed by RT-PCR analysis of osteoblast markers. This study suggests that several irradiation parameters and variations in the methods should be clearly established in the laboratory before laser treatment becomes a postulated application for bone tissue regeneration in clinical level.

Red (635 nm), Near-Infrared (808 nm) and Violet-Blue (405 nm) Photobiomodulation Potentiality on Human Osteoblasts and Mesenchymal Stromal Cells: A Morphological and Molecular In Vitro Study

“…Indeed, we demonstrated that as compared to 405 nm, 635 nm in osteoblasts induced: (i) an increase of the expression of vinculin, one of the mechanosensing adhesion protein by which osteoblasts sense matrix stiffness, recognized as a critical regulator of different osteoblast processes including growth, migration, differentiation as well as phenotype maintenance [ 37 , 38 ]; and (ii) an upregulation of all tested osteogenic differentiation markers, namely Runx-2, ALP, OPN as well as an increase of mineralized bone-like nodule structure formation. Our results agree with a recent report showing that PBM with 635 nm did not affect viability and proliferation of CRL-11372 osteoblast-like cells [ 30 ]. In contrast with our findings, that study showed no significant stimulatory effects of this PBM treatment on osteoblast differentiation; this may be dependent on the different responsiveness of the two osteoblast-like cell types to red light or on the different laser parameters used, such as the higher energy doses (0.5, 1, 2 J/cm 2 ).…”

“…However, in our experimental model, 808 nm did not up-regulated, in osteoblasts, neither the expression of OPN nor ALP, which is in agreement with the research by Emes et al [ 78 ] on rat calvarial osteoblast-like cells, by Bölükbaşı Ateş et al [ 30 ] on human CRL-11372 osteoblast like-cells and by Pagin et al [ 79 ] on pre-osteoblasts MC3TR; moreover, such treatment, in hMSCs, reduced the expression of Runx-2 and did not augment that of ALP in accordance to Bouvet-Gerbettaz et al [ 80 ].…”

“…However, at present, univocal standardized guidelines for the use of PBM for osteoregenerative purposes are not available. This is mainly dependent on the variety of wavelengths, medical laser and LED types used with disparate energy output modes and setting parameters, which has produced many different treatment protocols with different and sometimes contradictory outcomes [ 13 , 20 , 21 , 26 , 29 , 30 ] hampering meaningful comparison of the results and demanding a skeptical look for the potential beneficial effects of this approach. Moreover, this scenario is complicated by the fact that a biphasic-dose cellular response to the same wavelength has been frequently observed with low levels of light that are more effective than the higher ones on stimulating cell functionality [ 31 ] In addition, the molecular mechanisms by which PBM induces different biological responses have not been fully clarified.…”

Portable Multicolor LED-Based System for the Photobiomodulation Therapy on Wound Healing Process In Vitro

“…Thus, light with improved optical instruments has become a revolutionary breakthrough in the eld of medicine and biomedical sciences [3]. Among various application areas, light can be used to destroy pathogens or cancer cells [4][5][6] and also promote cell proliferation and differentiation [7,8]. Photobiomodulation is speci cally used to stimulate or inhibit cellular processes by changing cellular biochemical activities with the absorption of photon energy by certain cellular components at non-thermal and low-level irradiances [9].…”

Treatment Outcome of Two Short Implant Retained Mandibular Overdenture in Combination With Photobiomodulation

“…Photobiomodulation (PBM) has demonstrated to be a potentially effective modality in accelerating the healing process and enhancing bone formation (14)(15)(16)(17)(18). Given the successful application of non-ablative lasers to boost formation of new bone, this promising treatment modality was employed by researchers to accelerate healing of peri-implant bone in attempt to shorten the healing time before definitive prosthesis insertion.…”