Comparative transcriptome analysis of gene expression patterns on B16F10 melanoma cells under Photobiomodulation of different light modes

Effect of 460 nm blue light PBM on human MeWo melanoma cells

Photobiomodulation (PBM) using 460 nm blue light has been shown to have an inhibitory effect on skin cancer cells. In this study, we used a continuous LED light source with a wavelength of 460 nm and designed various combinations of power density (ranging from 6.4 to 25.6 mW) and dose (ranging from 0.96 to 30.72 J/cm2) to conduct treatment experiments on MeWo cells to investigate the effects of blue light on MeWo melanoma cells. We are focusing on cell viability, cytotoxicity, mitochondrial function, oxidative stress, and apoptosis. We found that blue light inhibits these melanoma cells through oxidative stress and DNA damage, and this inhibition intensifies at higher irradiance levels. Although the cells initially attempt to resist the stress induced by the treatment, they eventually undergo apoptosis over time. These findings contribute to understanding melanoma's molecular response to blue light PBM, lay the groundwork for future clinical applications.

The role of photobiomodulation in accelerating bone repair

Bone repair is faced with obstacles such as slow repair rates and limited bone regeneration capacity. Delayed healing even nonunion could occur in bone defects, influencing the life quality of patients severely. Photobiomodulation (PBM) utilizes different light sources to derive beneficial therapeutic effects with the advantage of being non-invasive and painless, providing a promising strategy for accelerating bone repair. In this review, we summarize the parameters, mechanisms, and effects of PBM regulating bone repair, and further conclude the current clinical application of PBM devices in bone repair. The wavelength of 635-980 nm, the output power of 40-100 mW, and the energy density of less than 100 J/cm2 are the most commonly used parameters. New technologies, including needle systems and biocompatible and implantable optical fibers, offer references to realize an efficient and safe strategy for bone repair. Further research is required to establish the reliability of outcomes from in vivo and in vitro studies and to standardize clinical trial protocols.

Effect of photobiomodulation on alleviating primary dysmenorrhea caused by PGF2α

Photobiomodulation (PBM) has attracted widespread attention in suppressing various pain and inflammation. Primary dysmenorrhea (PD) primarily occurs in adolescents and adult females, and the limited effectiveness and side effects of conventional treatments have highlighted the urgent need to develop and identify new adjunct therapeutic strategies. In this work, the results of pain and PGs demonstrated that 850 nm, 630 nm, and 460 nm all exhibited pain inhibition, decreased PGF2α and upregulated PGE2, while 630 nm PBM has better effectiveness. Then to explore the underlying biological mechanisms of red light PBM on PD, we irradiated prostaglandin-F2α induced HUSM cells and found that low-level irradiance can restore intracellular calcium ion, ROS, ATP, and MMP levels to normal levels. And, red light enhanced cell viability and promoted cell proliferation for normal HUSM cells. Therefore, this study proposes that red light PBM may be a promising approach for the future clinical treatment of PD.

Blue light photobiomodulation induced apoptosis by increasing ROS level and regulating SOCS3 and PTEN/PI3K/AKT pathway in osteosarcoma cells

Blue light photobiomodulation (PBM) has attracted great attention in diminishing proliferation and inducing death of cancer cells recently. Osteosarcoma (OS) primarily occurring in children and adolescents, the limitations of drug resistance and limb salvage make it urgent to develop and identify new adjuvant therapeutic strategies. In this work, we attempted to research the anticancer effects and biological mechanisms of blue light PBM in human OS MG63 cells. The effects of various blue light parameters on MG63 cells indicated that suppressed cell proliferation and cell migration, induced cell apoptosis which are experimentally assessed using multiple assays including CCK, LDH, wound healing assay and Hoechst staining. Concurrently, the increases of ROS level and the inhibition of PI3K and AKT expression were identified under high-dose blue light PBM in MG63 cells. Meanwhile, SOCS3 is a major inducible anti-tumor molecule, we also found that blue light LED substantially promoted its expression. Thus, this study proposed that bule light PBM may be a hopeful therapeutic approach in OS clinical treatment in the future.

Photoinactivation of Escherichia coli by 405 nm and 450 nm light-emitting diodes: Comparison of continuous wave and pulsed light

BACKGROUND

Antimicrobial blue light (ABL) therapy is one of the novel non-antibiotic approaches and recent studies showed the potential of pulsed ABL.

PURPOSE

Comparing photoinactivation effect of continuous wave (CW) and pulsed blue light and investigating the impact of varying light parameters.

METHODS

E. coli cells in planktonic were treated with CW and pulsed light (405 nm and 450 nm) at 60 mW/cm2, and the samples were taken to assess survival, reactive oxygen species (ROS) level, damage of cell membrane and metabolic activity. Further, a ROS scavenger was used to find the role of ROS played in ABL therapy.

RESULTS

E. coli was more sensitive to 405 nm light and the photoinactivation was dose-dependent. Pulsed 405 nm light showed the better antimicrobial effect on E. coli and caused increasing damage of cell membrane. It might be attributed to the ROS production in bacteria.

CONCLUSION

Pulsed light has a potential of improving the efficacy of ABL therapy and is worth to be explored deeply further.

Effect of blue light on the cell viability of A549 lung cancer cells and investigations into its possible mechanism

Blue light has attracted extensive attention as a new potential cancer therapy. Recent studies have indicated that blue light has a significant inhibition effect on A459 cells. However, the effect of light parameters on the treatment of A549 cells and the mechanism of how blue light made the effect was still unclear. This study aimed to investigate A549 cells responses to blue light with varying irradiance and dose-dense, and tried to find out the mechanism of the effects blue light made. The results suggested that the responses of A549 cells to blue light with different irradiance and dose-dense were different and the decrease of cell viability reached saturation when the irradiance reached 3 mW/cm2 and the dose-dense reached 3.6 J/cm2 . It was assumed that blue light suppressed PI3K/AKT pathway and promoted the expression of JNK and p53 to affect the proliferation of A549 cells.

The pulse light mode enhances the effect of photobiomodulation on B16F10 melanoma cells through autophagy pathway

Photobiomodulation (PBM) is the use of low irradiance light of specific wavelengths to generate physiological changes and therapeutic effects. However, there are few studies on the effects of PBM of different LED light modes on cells. Here, we investigated the difference of influence between continuous wave (CW) and pulse-PBM on B16F10 melanoma cells. Our results suggested that the pulse mode had a more significant PBM than the CW mode on B16F10 melanoma cells. Our study confirmed that ROS and Ca2+ levels in B16F10 melanoma cells treated with pulse-PBM were significantly higher than those in the control and CW-PBM groups. One mechanism that causes the difference in CW and pulse-PBM action is that pulse-PBM activates autophagy of melanoma cells through the ROS/OPN3/Ca2+ signaling pathway, and excessive autophagy activation inhibits proliferation and apoptosis of melanoma cells. Autophagy may be one of the reasons for the difference between pulse- and CW-PBM on melanoma cells. More importantly, melanoma cells responded to brief PBM pulses by increasing intracellular Ca2+ levels.

Progress of phototherapy for osteosarcoma and application prospect of blue light photobiomodulation therapy

Osteosarcoma (OS) is the most common primary malignant bone tumor that mainly affects the pediatric and adolescent population; limb salvage treatment has become one of the most concerned and expected outcomes of OS patients recently. Phototherapy (PT), as a novel, non-invasive, and efficient antitumor therapeutic approach including photodynamic therapy (PDT), photothermal therapy (PTT), and photobiomodulation therapy (PBMT), has been widely applied in superficial skin tumor research and clinical treatment. OS is the typical deep tumor, and its phototherapy research faces great limitations and challenges. Surprisingly, pulse mode LED light can effectively improve tissue penetration and reduce skin damage caused by high light intensity and has great application potential in deep tumor research. In this review, we discussed the research progress and related molecular mechanisms of phototherapy in the treatment of OS, mainly summarized the status quo of blue light PBMT in the scientific research and clinical applications of tumor treatment, and outlooked the application prospect of pulsed blue LED light in the treatment of OS, so as to further improve clinical survival rate and prognosis of OS treatment and explore corresponding cellular mechanisms.

The review of the light parameters and mechanisms of Photobiomodulation on melanoma cells

Photobiomodulation (PBM) uses low-intensity visible or near-infrared light to produce beneficial effects on cells or tissues, such as brain therapy, wound healing. Still there is no consistent recommendation on the parameters (dose, light mode, wavelength, irradiance) and protocols (repetition, treatment duration) for its clinical application. Herein, we summarize the current PBM parameters for the treatment of melanoma, and we also discuss the potential photoreceptors and downstream signaling mechanisms in the PBM treatment of melanoma cells. It is hypothesized that PBM may inhibit the melanoma cells by activating mitochondria, OPNs, and other receptors. Regardless of the underlying mechanisms, PBM has been shown to be beneficial in treating melanoma. Through further in-depth studies of the underlying potential mechanisms, it can strengthen the applications of PBM for the therapy of melanoma.