Gene Expression Analysis of Chondrogenic Markers in Hair Follicle Dermal Papillae Cells Under the Effect of Laser Photobiomodulation and the Synovial Fluid.

Introduction: Regarding the limited ability of the damaged cartilage cells to self-renew, which is due to their specific tissue structure, subtle damages can usually cause diseases such as osteoarthritis. In this work, using laser photobiomodulation and an interesting source of growth factors cocktail called the synovial fluid, we analyzed the chondrogenic marker genes in treated hair follicle dermal papilla cells as an accessible source of cells with relatively high differentiation potential. Methods: Dermal papilla cells were isolated from rat whisker hair follicle (Rattus norvegicus) and established cell cultures were treated with a laser (gallium aluminum arsenide diode Laser (λ=780 nm, 30 mW) at 5 J/cm2 ), the synovial fluid, and a combination of both. After 1, 4, 7, and 14 days, the morphological changes were evaluated and the expression levels of four chondrocyte marker genes (Col2a1, Sox-9, Col10a1, and Runx-2) were assessed by the quantitative real-time polymerase chain reaction. Results: It was monitored that treating cells with laser irradiation can accelerate the rate of proliferation of cells. The morphology of the cells treated with the synovial fluid altered considerably as in the fourth day they surprisingly looked like cultured articular chondrocytes. The gene expression analysis showed that all genes were up-regulated until the day 14 following the treatments although not equally in all the cell groups. Moreover, the cell groups treated with both irradiation and the synovial fluid had a significantly augmented expression in gene markers. Conclusion: Based on the gene expression levels and the morphological changes, we concluded that the synovial fluid can have the potential to make the dermal papilla cells to most likely mimic the chondrogenic and/or osteogenic differentiation, although this process seems to be augmented by the irradiation of the low-level laser.

Laser irradiation on growth of trichophyton rubrum: an in vitro study.

INTRODUCTION: Trichophyton rubrum is one of the most common species of dermatophytes which affects superficial keratinous tissue. It is not especially virulent but it can be responsible for considerable morbidity. Although there are different therapeutic modalities to treat fungal infections, clinicians are searching for alternative treatment because of the various side effects of the present therapeutic methods. As a new procedure, Laser therapy has brought on many advantages in clinical management of dermatophytes. Possible inhibitory potential of laser irradiation on fungal colonies was investigated invitro in this study. METHODS: A total of 240 fungal plates of standard size of trichophyton rubrum colonies that had been cultured from the lesions of different patients at the mycology laboratory, were selected. Each fungal plate was assigned as control or experimental group. Experimental plates were irradiated by a laser system (low power laser or different wavelength of high power laser). The effects of different laser wavelengths and energies on isolated colonies were assessed. After laser irradiation, final size of colonies was measured on the first, the 7th and the 14th day after laser irradiation. RESULTS: Although low power laser irradiation did not have any inhibitory effect on fungal growth, the Q-Switched Neodymium-Doped Yttrium Aluminium Garnet (Nd:YAG) laser 532nm at 8j/cm(2), Q-Switched Nd:YAG laser 1064nm at 4j/cm(2) to 8j/cm(2) and Pulsed dye laser 595nm at 8j/cm(2) to 14j/cm(2) significantly inhibited growth of trichophyton rubrum in vitro. CONCLUSION: Q-Switched Nd:YAG 532nm at 8j/cm(2), Q-Switched Nd:YAG laser 1064nm at 4j/cm(2) to 8j/cm(2) and pulsed dye laser (PDL) 595nm at 8j/cm(2) to 14j/cm(2) can be effective to suppress trichophyton rubrum growth.

Interferometry technique to eliminate noise in interference data based on a Mach-Zehnder interferometer.

Some experiments based on interferometry, such as studying refractive index changes, need a long time to be completed, and any movement or oscillation in the order of wavelength during that time may wash out the interference fringes or at least reduce the quality of the interferogram. In this work, a new technique is presented to enhance the interferometric data during such experiments. The main idea behind this technique is the use of a reference beam to monitor all surrounding changes during the experiment. Laser light was divided into two parallel beams and then entered into a Mach-Zehnder interferometer. One of the beams was used as a reference signal to measure interferometer drift and the other one was passed through the sample to measure the refractive index changes simultaneously in a single interferometer. Noise was extracted from the data with a written computer code to achieve a noise-free output.

Fabrication of channel waveguides in dye-doped polymer films by a beam-processing machine based on photo induced bleaching.

Irreversible changes in the refractive index of a dye-doped polymer film by photo induced bleaching were measured with a Mach-Zehnder interferometer. The decrease in the refractive index of the film for various laser powers and various radiation times has been investigated. A beam-processing machine with two simultaneous outputs has been designed to make use of this change in the refractive index to fabricate a channel waveguide. This method is simple and one step, and does not involve any solvent or mask; and also due to photobleaching, the pattern is not reversible.