The Effects of Photobiomodulation on Vocal Fold Wound Healing: In Vivo and In Vitro Studies

Effects of photobiomodulation on adipocytic infiltration in sites of skin healing: in vivo experimental study

Adipocyte infiltration consists of a temporary increase in the number of adipocytes in the microenvironment of tissue injury. There is already evidence in the literature of adipocytes' participation in promoting the inflammatory response, and parallelly laser photobiomodulation can benefit the tissue repair process. This study aimed to chronologically analyze adipocytic infiltration in the repair of photobiomodulated skin wounds experimentally induced in rats through histomorphometric analysis. The sample consisted of 20 rats divided into 2 groups: control group and group subjected to laser photobiomodulation. The skin portions of the back of rats were processed and stained with Hematoxylin-Eosin in 4 μm thick sections including the surgical wound 5 and 10 days after the proposed treatments. Qualitative and quantitative analyses were performed by capturing images of tissue sections, describing the organizational pattern of adipocytes around the surgical wound and counting individual adipocytes in the connective tissue in formation. Adipocytic infiltration was observed in both experimental groups on the 5th day, with a decrease on the 10th day. The group treated with photobiomodulation presented a greater number of adipocytes compared to the control group, in both periods analyzed. The findings of the present study seem to corroborate the literature, which indicates that adipose cells might stimulate inflammation and repair, and photobiomodulation can enhance these effects, since it aids the process of adipocytic infiltration in the injured area. Clinical trial number: Not applicable.

Reducing the gap between science and clinic: lessons from academia and professional practice - part B: traditional vocal therapy techniques and modern electrostimulation and photobiomodulation techniques applied to vocal rehabilitation

This text is the continuation of the XVIII SBFa Congress publication. In part "A" we presented the analyses on clinical vocal evaluation. Part "B" focuses on vocal rehabilitation: 4. Traditional techniques of vocal therapy; 5. Modern techniques of electrostimulation and photobiomodulation applied to vocal rehabilitation. The numerous studies on the various programs, methods, and techniques of traditional rehabilitation techniques, and many with high quality of evidence, allow us to consider such procedures relatively well described, safe, and with known effects, accounting for the treatment of various vocal disorders. The scientific evidence with traditional techniques is recognized worldwide. New fronts of evolution, with electrostimulation or photobiomodulation used to handle voice problems, seem to be promising as coadjutant approaches. There are more studies on electrostimulation in vocal rehabilitation than with photobiomodulation; however, scientific evidence for these two modern techniques is still limited. Knowledge and caution are required for the application of either technique.

Reducing the gap between science and clinic: lessons from academia and professional practice - part B: traditional vocal therapy techniques and modern electrostimulation and photobiomodulation techniques applied to vocal rehabilitation

ABSTRACT This text is the continuation of the XVIII SBFa Congress publication. In part “A” we presented the analyses on clinical vocal evaluation. Part “B” focuses on vocal rehabilitation: 4. Traditional techniques of vocal therapy; 5. Modern techniques of electrostimulation and photobiomodulation applied to vocal rehabilitation. The numerous studies on the various programs, methods, and techniques of traditional rehabilitation techniques, and many with high quality of evidence, allow us to consider such procedures relatively well described, safe, and with known effects, accounting for the treatment of various vocal disorders. The scientific evidence with traditional techniques is recognized worldwide. New fronts of evolution, with electrostimulation or photobiomodulation used to handle voice problems, seem to be promising as coadjutant approaches. There are more studies on electrostimulation in vocal rehabilitation than with photobiomodulation; however, scientific evidence for these two modern techniques is still limited. Knowledge and caution are required for the application of either technique.

Phonosurgery: A review of current methodologies

Cold-steel has served as the gold standard modality of phonosurgery for most of its history. Surgical laser technology has revolutionized this field with its wide use of applications. Additional modalities have also been introduced such as coagulative lasers, photodynamic therapy, and cryotherapy. This review will compare the surgical modalities of cold steel, surgical lasers, phototherapy and cryotherapy. The mechanism of action, tissue effects and typical uses will be addressed for each modality.

Therapeutic effects of photobiomodulation in the speech-language-hearing clinic: an integrative literature review

ABSTRACT Purpose: to conduct a literature review on the therapeutic effects of photobiomodulation applicable to speech-language-hearing therapy. Methods: the databases searched were the Cochrane Library, Virtual Health Library, Medical Literature Analysis and Retrieval System Online (MEDLINE) via PubMed, and Web of Science/ISI.The selected articles were original ones whose abstracts were available and that evaluated the therapeutic effect of photobiomodulation in situations related to speech-language-hearing practice. Results: the sample comprised 23 articles, most of them being indexed in PubMed. The fields of health with the largest number of publications were Physical Therapy and Medicine. The sample size ranged from1 to 99 people, aged 15 to 77 years, and the most applied wavelength was the infrared one. Most of the studies had positive photobiomodulation application results - although in a few publications the effects of this treatment modality were assessed in a combination with rehabilitation exercises. Conclusion: photobiomodulation benefits different disorders treated by speech-language-hearing therapists, however, there is a broad methodological diversity, lacking specific protocols for the ideal dosimetry for each disorder.

In Vitro Evidences of Different Fibroblast Morpho-Functional Responses to Red, Near-Infrared and Violet-Blue Photobiomodulation: Clues for Addressing Wound Healing

Although photobiomodulation (PBM) has proven promising to treat wounds, the lack of univocal guidelines and of a thorough understanding of light–tissue interactions hampers its mainstream adoption for wound healing promotion. This study compared murine and human fibroblast responses to PBM by red (635 ± 5 nm), near-infrared (NIR, 808 ± 1 nm), and violet-blue (405 ± 5 nm) light (0.4 J/cm2 energy density, 13 mW/cm2 power density). Cell viability was not altered by PBM treatments. Light and confocal laser scanning microscopy and biochemical analyses showed, in red PBM irradiated cells: F-actin assembly reduction, up-regulated expression of Ki67 proliferation marker and of vinculin in focal adhesions, type-1 collagen down-regulation, matrix metalloproteinase-2 and metalloproteinase-9 expression/functionality increase concomitant to their inhibitors (TIMP-1 and TIMP-2) decrease. Violet-blue and even more NIR PBM stimulated collagen expression/deposition and, likely, cell differentiation towards (proto)myofibroblast phenotype. Indeed, these cells exhibited a higher polygonal surface area, stress fiber-like structures, increased vinculin- and phospho-focal adhesion kinase-rich clusters and α-smooth muscle actin. This study may provide the experimental groundwork to support red, NIR, and violet-blue PBM as potential options to promote proliferative and matrix remodeling/maturation phases of wound healing, targeting fibroblasts, and to suggest the use of combined PBM treatments in the wound management setting.