Photobiomodulation Increases Viability in Full-Thickness Grafts in Rats Submitted to Nicotine.

BACKGROUND AND OBJECTIVES: Photobiomodulation (PBM) therapy with 830 nm wavelength or 660 wavelength to compare the effects with parameters of 30 mW, 0.028 cm2 , 9.34 seconds, and 3.64 J on the total integration of total skin grafts in rats submitted to nicotine. STUDY DESIGN/MATERIALS AND METHODS: Sixty male Wistar rats were divided in six groups: Sham-skin-grafting surgery; 830 nm-skin-grafting followed by 830 nm irradiation; 660 nm-skin grafting followed by 660 nm irradiation; Nicotine-subjected to subcutaneous nicotine injection (2 mg/kg twice a day for 4 weeks), followed by skin grafting; Group Nicotine/830 nm-similar to Group Nicotine, followed by 830 nm irradiation; Group Nicotine/660 nm-similar to Group Nicotine, followed by 660 nm irradiation. The percentage contraction of the grafting tissue was evaluated through ImageJ®. The thickness of the epidermis, inflammatory infiltrates, and the space between the implanted tissue and receptor bed were determined by histology; and the expression of vascular growth factor and blood vessel density (factor VIII) were evaluated by immunohistochemistry. RESULTS: The PBM at both wavelengths promoted a facilitating effect on the integration of the skin graft under nicotine and had a more significant effect on the thickness of the epidermis and expression of angiogenesis without nicotine at a wavelength of 830 nm. Different wavelengths influence responses related to the viability of cutaneous grafts in rats submitted to nicotine. CONCLUSIONS: The PBM with 830 nm and 660 nm promoted beneficial results in skin grafts submitted to the deleterious action of nicotine. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Low-level laser therapy ameliorates disease progression in a mouse model of multiple sclerosis.

Multiple sclerosis (MS) is an autoimmune demyelinating inflammatory disease characterized by recurrent episodes of T cell-mediated immune attack on central nervous system (CNS) myelin, leading to axon damage and progressive disability. The existing therapies for MS are only partially effective and are associated with undesirable side effects. Low-level laser therapy (LLLT) has been clinically used to treat inflammation, and to induce tissue healing and repair processes. However, there are no reports about the effects and mechanisms of LLLT in experimental autoimmune encephalomyelitis (EAE), an established model of MS. Here, we report the effects and underlying mechanisms of action of LLLT (AlGaInP, 660 nm and GaAs, 904 nm) irradiated on the spinal cord during EAE development. EAE was induced in female C57BL/6 mice by immunization with MOG35-55 peptide emulsified in complete Freund's adjuvant. Our results showed that LLLT consistently reduced the clinical score of EAE and delayed the disease onset, and also prevented weight loss induced by immunization. Furthermore, these beneficial effects of LLLT seem to be associated with the down-regulation of NO levels in the CNS, although the treatment with LLLT failed to inhibit lipid peroxidation and restore antioxidant defense during EAE. Finally, histological analysis showed that LLLT blocked neuroinflammation through a reduction of inflammatory cells in the CNS, especially lymphocytes, as well as preventing demyelination in the spinal cord after EAE induction. Together, our results suggest the use of LLLT as a therapeutic application during autoimmune neuroinflammatory responses, such as MS.