• Korean Journal of Optics and Photonics
• /
• v.34 no.2
• /
• pp.45-52
• /
• 2023

In this study, we have investigated the effect of photobiomodulation (PBM) on corneal wound healing, using a low-power light-emitting diode (LED) at different wavelengths. We found that LEDs with wavelengths ranging from 623 to 940 nm had no significant cytotoxic effects on corneal epithelial cells. The effect of PBM on promoting cell migration was analyzed by scratch assay, and it was found that PBM at 623 nm significantly increased cell migration and promoted wound healing. Furthermore, the expression of genes related to cell migration and wound healing was analyzed, and it was found that PBM at 623 nm upregulated the expression of the genes FGF-1 and MMP2, which are known to promote cell proliferation and extracellular matrix degradation. These findings suggest that PBM with low-powered light at specific wavelengths, particularly 623 nm, could be utilized to treat corneal injury.

• Korean Journal of Optics and Photonics
• /
• v.32 no.5
• /
• pp.235-243
• /
• 2021

Photobiomodulation (PBM)-based therapy, which uses a phenomenon in which a light source of a specific wavelength band promotes ATP production in mitochondria, has attracted much attention in the fields of biology and medicine because of its effects on wound healing, inflammation reduction, and pain relief. Research on PBM-based therapy has mainly used lasers and light-emitting diodes (LEDs) as light sources and, despite the advantages of organic light-emitting diodes (OLEDs), there have been only a few cases where OLEDs were used in PBM-based therapy. In this research, the skin-care effect of PBM was analyzed using red (λ = 620 nm), green (λ = 525 nm), and blue (λ = 455 nm) OLED lighting modules, and was compared to the PBM effect of LEDs. We demonstrated the PBM-based skin-care effect of the red, green, blue OLED lighting modules by measuring the increase in the amount of collagen type-1 synthesis, the inhibition of melanin synthesis, and the suppression of nitric oxide generation, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.22 no.5
• /
• pp.431-435
• /
• 2009

The apparatus has been fabricated using the laser diode and microprocessor unit. The apparatus used a InGaAlP laser diode for laser medical therapy and was designed for a pulse width modulation type to increase stimulation effects. To raise the stimulus effect of the human body, the optical irradiation frequency could be set up. The study has executed in-vivo experiment by employing our own developed laser diode irradiation system to investigate the effects of the InGaAlP laser diode irradiation on the wound healing as a preliminary study aimed at the application of InGaAlP laser diode to wound healing of human skin injury. The study cut out whole skin layers of Sprague-Dawley rat on the back part in 1 cm circle and observed developing effects after executing light irradiation for 9 days, and in result it is found that the light irradiation rat showed earlier wound healing than non-irradiation rat during the experimental period. In addition, there are some differences found regarding the healing process between laser diode irradiated rats and non-irradiated ones.

• Medical Lasers
• /
• v.10 no.2
• /
• pp.96-105
• /
• 2021

Background and Objectives Skin aging is reportedly associated with regulation in collagen and elastin synthesis. This study investigated the potential of combining light-emitting diode (LED) treatments using a 630-nm and 850-nm LED with simultaneous microcurrent application. Materials and Methods The dorsal skin of female pigs was treated with a home-use device. We examined the treatment effects using photography, thermocamera, microscopic pathology, and histological examination to determine the mechanism of action, efficacy, and safety of the procedure. A histological observation was performed using hematoxylin and eosin, Masson's trichrome, Victoria blue, and immunohistochemical staining. We also used the Sircol soluble collagen and elastin assay kit to measure the amounts of collagen and elastin in the porcine back skin tissue after 2 and 6 weeks. Results Evaluation by visual inspection and devices showed no skin damage or heat-induced injury at the treatment site. Histological staining revealed that accurate treatment of the targeted dermis layer effectively enhanced collagen and elastin deposition. Collagen type I, a protein defined by immunohistochemical staining, was overexpressed in the early stages of weeks 2 and 6. Combined therapy findings showed the superior capability of the 630-nm and 850-nm LED procedures to induce collagen; in contrast, elastin induction was more pronounced after microcurrent treatments. Conclusion The home-use LED device, comprising a combination of 630-nm and 850-nm LEDs and microcurrent, is safe and can be used as an adjunctive treatment for self-administered facial rejuvenation.

• Medical Lasers
• /
• v.10 no.4
• /
• pp.207-213
• /
• 2021

Background and Objectives This study was undertaken to assess the stability and efficacy of laser therapy (808 nm), Liquiband (a commercial topical skin adhesive product), and a combination treatment, for application in oral ulcers. Materials and Methods The oral ulcer rat animal model was used to determine the efficacy of photobiomodulation, Liquiband, or combination therapy. Ulcers were induced by injecting 60% acetic acid in the oral mucosa. Three days after ulcer confirmation, the chemically induced ulcers were treated with either laser (808 nm), Liquiband, or a combination of both, every two days for 8 days (4 sessions). Combination therapy was performed by first treating with laser followed by application of the Liquiband. Reduction in ulcer area size was subsequently determined, and animals were sacrificed at 5 and 10 days after the last administration, for histological observation of the extracted oral ulcer tissue samples. Results In this study, treatment with either laser (808 nm) or commercial Liquiband product as well as the combined treatment significantly enhanced oral ulcer healing in the rat animal model. The effect of laser treatment is mainly attributed to collagen synthesis, whereas application of the Liquiband promotes vascularization and formation of granulation tissue. Our results indicate that further optimization of the combined therapy could synergistically and significantly enhance oral ulcer healing. Conclusion Laser or Liquiband treatment of oral ulcer in the rat animal model exert different outcomes, but both methods confirm significant effects relative to the untreated group. The combined treatment group with laser and Liquiband showed marked oral ulcer healing, but further optimization is required to get highly significant results and establish the potential synergistic effect of the combination therapy, as compared to the individual enhancing effects of healing oral ulcers.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.26 no.5
• /
• pp.481-489
• /
• 2000

This research was focused on overall examination of tissue alteration, wound healing promotion. After the hair on the dorsal surface was shaved, $5{\times}5mm$ oval skin defect was formed. Experimental wounds of right side were irradiated on every day for 90 second with Ga-Al-As semi-conductor laser. Left side wounds served as control group. The rats were sacrificed on the 1st, 3rd, 5th, 7th, 14th, 21th day. For light microscopically, parafin section were stained with H&E, MT. The outcomes were as follows : 1. On 1st day, experimental and control group were seen acute inflammatory cell infiltration, edema. 2. On the 3rd days, both groups were seen crust development, collagen, blood vessel proliferation. 3. On the 5th days, experimental group were reduced edema and inflammatory cell infiltration than control group. 4. On the 7th days, both groups were observed edema, inflammatory cell infiltration disappearance and keratinocytes motility from wound defect. 5. On the 14th days, experimental group appeared collagen, blood vessel proliferation and hair follicle than control group. 6. On the 21th days, both groups were seen normal status re-epithelization. According to the above results, The wound-healing stimulated by laser radiation involves an increased rate of epithelial growth. LLLT was confirmed that it has fibroblast, blood vessel proliferation, influence initial wound healing process.

• Korean Journal of Acupuncture
• /
• v.22 no.2
• /
• pp.163-181
• /
• 2005

Objective: The purpose of this study is to review research papers on low level laser therapy (LLLT) and to improve the knowledge of LLLT field. Methods: For introduction, laser characteristics, including wavelength, medium, beam size, power, and unit power were explained. In order to understand LLLT, tissue optics and light-biomatter interaction were briefly mentioned. We reviewed 21 Korean papers on laser acupuncture and LLLT on the viewpoint of laser apparatus. Results and Conclusion: We found that the description of laser apparatus employed for LLLT experiments were not fully written. Laser wavelength and power which are the most crucial parameters, were omitted in several papers. No paper had information on beam size. In order to have high efficacy, laser should be used with proper laser parameters. Conditions of irradiation area or acupoints should be considered too. Some future technology on laser acupuncture were mentioned.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.572-573
• /
• 2010

This paper performed the basic study for fabricating the low level laser therapy apparatus, and one of the goals of this paper was to make this apparatus used handily. The equipment was fabricated using the 655nm laser diode and microcontroller unit and designed to enable us to control light irradiation time, and reservation.. In case of cell proliferation experiment, each experiment was performed to irradiation group and non-irradiation group for bome marrow cell. MTT assay method was chosen to verify the cell increase of two groups and the effect of irradiation on cell proliferation was examined by measuring.

• Journal of the Optical Society of Korea
• /
• v.17 no.4
• /
• pp.289-295
• /
• 2013

Although low-level laser therapy (LLLT) has been a valuable therapeutic technology in the clinic, its efficacy may be reduced in deep tissue layers due to strong light scattering which limits the photon density. In order to enhance the photon density in deep tissue layers, this study developed an optical tissue clearing (OTC) laser probe (OTCLP) system which can utilize four different OTC methods: 1) tissue temperature control from 40 to $10^{\circ}C$; 2) laser pulse frequency from 5 to 30 Hz; 3) glycerol injection at a local region; and 4) a combination of the aforementioned three methods. The efficacy of the OTC methods was evaluated and compared by investigating laser beam profiles in ex-vivo porcine skin samples. Results demonstrated that total (peak) intensity at full width at half maximum of laser beam profile when compared to control data was increased: 1) 1.21(1.39)-fold at $10^{\circ}C$; 2) 1.22 (1.49)-fold at a laser pulse frequency of 5 Hz; 3) 1.64 (2.41)-fold with 95% glycerol injection; 4) 1.86 (3.4)-fold with the combination method. In conclusion, the OTCLP system successfully improved the laser photon density in deep tissue layers and may be utilized as a useful tool in LLLT by increasing laser photon density.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.24 no.5
• /
• pp.341-350
• /
• 2024

Background: Achieving successful pain control and adequate anesthesia through an inferior alveolar nerve block for endodontic treatment in cases with symptomatic irreversible pulpitis (SIP) is difficult, especially in mandibular molars. This study was designed to compare the effect of oral medication with ibuprofen and soft laser therapy on inferior alveolar nerve block during endodontic treatment. Methods: The trial comprised 180 patients (45 each group) with SIP. Four groups of patients were created: group 1 received 400 mg of ibuprofen; group 2 received soft laser irradiation; group 3 received a combination of soft laser and ibuprofen 400 mg; and group 4 received a placebo 1 h prior to local anesthesia. Patients recorded their pain scores on the Heft-Parker visual analog scale (VAS) before the start of intervention, 15 min after anesthesia, during access cavity preparation, and ultimately during root canal instrumentation. Each patient also rated their level of discomfort on a VAS. Every stage with no or minimal discomfort was deemed successful. The chi-square, Kruskal-Wallis, and one-way analysis of variance tests were used to evaluate the data. Results: The best success rate was achieved for soft laser ibuprofen combination, ibuprofen and soft laser groups reported similar success results, and control group recorded the least pain scores. The mean pain scores were lowest for group 3 and highest for group 4 (P < 0.001). Ibuprofen and soft laser combination was significantly better than control group (P < 0.001). There was no significant difference between ibuprofen and laser groups (P = 0.24). Conclusions: For teeth with irreversible pulpitis, preoperative ibuprofen treatment combined with soft laser irradiation greatly improved the success rates of inferior alveolar nerve block anesthesia.