Photomodulative effects of low-level laser therapy on tracheal fenestration developed in in vivo model.

The effect of low-level laser therapy (LLLT) on variable mucosal lesions in the upper aerodigestive tract has been reported. However, the effect of LLLT on tracheostomy sites or tracheal fenestration is rarely reported. In this study, we evaluate the effect of LLLT performed using 635 nm laser light based on a cylindrical diffuser and an animal model with tracheal fenestration. An animal model of tracheal fenestration is developed by suturing the trachea to the skin after performing a vertical tracheostomy from the second to the fifth tracheal ring of Wistar rats (male, body weight 200-250 g). LLLT (spot size: 2 cm2) is conducted once daily for five days using a handheld cylindrical device. Twenty-four rats are randomly assigned to a no-therapy or LLLT group with an energy density of 20 J/cm2. Histological analysis is performed at 7 and 14 days after tracheal fenestration. Irradiation at the tracheal fenestration site with an energy density of 20 J/cm2 improves the wound healing, as shown at 2 weeks after tracheostomy. Histological analysis shows significantly decreased acute inflammation and granulation tissue, as well as better cartilage regeneration and less tracheal wall thickening. Therefore, LLLT demonstrates therapeutic potential for preventing tracheal stenosis and granuloma after tracheostomy.

Cellulose nanofibrils reinforced chitosan-gelatin based hydrogel loaded with nanoemulsion of oregano essential oil for diabetic wound healing assisted by low level laser therapy.

Diabetic foot ulcers are imperfections in the process of wound healing due to hyperglycemic conditions. Here, a nanoemulgel fabricated with oregano essential oil nanoemulsion, assisted by low-level laser therapy, was investigated for its efficacy in diabetic wound healing. A hydrogel- based healing patch, fabricated using biological polymers namely chitosan and gelatin and, polyvinyl pyrollidone. The hydrogel was reinforced with cellulose nanofibrils for enhanced stability and barrier properties. Nanoemulsion of oregano essential oil, with an average particle size of 293.7 ± 8.3 nm, was prepared via homogenization with chitosan as the coating agent. Nanoemulsion impregnated hydrogel, termed as the nanoemulgel, was assessed for its physio-mechanical properties and healing efficiency. The strong linkages in nanoemulgel demonstrated its large swelling capacity, high mechanical strength, and maximum thermal stability. The optimized conditions for low-level laser therapy using 808 nm were 1 W. cm-2 and 5 min. The optimized drug concentration of 128 µg. mL-1 exhibited viability of NIH/3 T3 fibroblasts as 75.5 ± 1.2 % after 24 h. Cell migration assay demonstrated that dual therapy facilitated wound healing, with a maximum closure rate of 100 % at 48 h. In vivo results revealed the rapid healing effects of the dual therapy in diabetic rat models with foot ulcers: a maximum healing rate of 97.5 %, minimum scar formation, increased granulation, enhanced reepithelialization, and a drastic decrease in inflammation and neutrophil infiltration within the treatment period compared to monotherapy and control. In summary, the combinatorial therapy of nanoemulgel and low-level laser therapy is a promising regimen for managing diabetic foot ulcers with a rapid healing effect.

Combined treatment of low-level laser therapy and phloroglucinol for inhibition of fibrosis.

BACKGROUND AND OBJECTIVES: Fibrosis is a highly prevalent disease, which is responsible for 45% of deaths through pathological effects in developed countries. Previous studies have reported that low-level laser therapy (LLLT) can modulate fibrotic activity, but significant enhancement of therapeutic efficacy is still required for clinical translation. The aim of this study is to evaluate the feasible effect of LLLT combined with phloroglucinol (PHL) on the inhibition of fibrosis in vitro. STUDY DESIGN/MATERIALS AND METHODS: NIH/3T3 murine embryonic fibroblasts cells were cultured and transforming growth factor-ß1 (TGF-ß1) was treated for transition of fibroblasts. After TGF-ß1 treatment, LLLT and PHL were used, respectively, and in combination to suppress fibrosis. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and BrdU assays were performed to estimate the cell viability and proliferation. To evaluate the expression of fibrotic markers, we used confocal immunofluorescence and western blot. RESULTS: When compared with respectively treated groups, the group with the combined treatment of LLLT and PHL significantly reduced cell viability and proliferation. Immunofluorescence staining showed that the combined group minimized more α-smooth muscle actin (α-SMA) and type I collagen than the other groups. Western blot analysis showed that the combined treatment had significant decreases in α-SMA, TGF-ß1, and type I collagen. CONCLUSIONS: PHL-assisted LLLT may be an effective treatment to inhibit fibrosis due to its additive effects. The combined treatment has a potential to be an alternative treatment for fibrosis. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

In vitro anti-tumor effect of low-power laser irradiation (LPLI) on gastroenterological carcinoma cells.

Primary hepatocellular carcinoma (HCC) and colon carcinoma are two of the most common clinical malignancies along with high morbidity and mortality. As low-power laser irradiation (LPLI) can induce cytotoxicity or cell apoptosis on several types of hyperplasia, LPLI may be a potential alternative treatment for gastroenterological cancers. The current in vitro study focused on LPLI-induced apoptosis and mechanism after 532-nm laser irradiation on two different carcinoma cells. Squamous cell carcinoma (VX2) and murine colon carcinoma (CT26) cells were cultured to test the feasibility of LPLI. The applied fluence varied from 0 to 600 J/cm2. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide analysis, fluorescence imaging, wound healing assay, and cell apoptosis tests were performed 24 h post-irradiation to monitor cellular responses. The current results demonstrated a dose-dependent stimulatory effect of LPLI on the cell viability, migration, and apoptosis of VX2 and CT26 cells. The therapeutic fluence of 600 J/cm2 induced statistically significant inhibition in cell viability. Both the wound healing assay and the cell apoptosis tests confirmed that LPLI with high fluences could inhibit cell migration as well as induce cell apoptosis. The current findings demonstrate that LPLI might be a potential treatment for the carcinoma cells. Further studies will be performed to evaluate the feasibility of LPLI in in vivo tumor models.