title: Tissue responses to postoperative laser therapy in diabetic rats submitted to excisional wounds.
abstract: In a previous study about low-level laser therapy biomodulation on a full-thickness burn model we showed that single and fractionated dose regimens increased wound healing and leukocyte influx similarly when compared with untreated control. In order to verify if this finding would be similar in an impaired wound model, we investigated the effect of single and multiple irradiations on wound closure rate, type of inflammatory infiltrate, myofibroblasts, collagen deposition, and optical retardation of collagen in diabetic rats. Female Wistar rats in the same estrous cycle had diabetes induced with streptozotocin and an 8-mm excisional wound performed with a punch. The experimental groups were: control group--untreated ulcer; single-dose group--ulcer submitted to single dose of diode laser therapy (λ = 660 ± 2 nm; P = 30 mW; energy density: 4 J/cm2) and fractionated-dose group--ulcer submitted to 1 J/cm2 laser therapy on Days 1, 3, 8, and 10. The ulcers were photographed on the experimental days and after euthanasia tissue samples were routinely processed for histological and immunohistochemistry analyses. Independently of the energy density, laser therapy accelerated wound closure by approximately 40% in the first three days in comparison to the control group. Laser therapy increased acute inflammatory infiltrate until Day 3. Both laser groups exhibited more myofibroblasts and better collagen organization than the control group. The findings demonstrate that low-level laser therapy in the immediate postoperative period can enhance the tissue repair process in a diabetes model. Similar effects were achieved with laser therapy applied a single time with an energy density of 4 J/cm2 and applied four times with an energy density of 1 J/cm2. The application of laser therapy in the inflammatory phase was the most important factor to the enhancement of the tissue repair process.
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Cristiano
authors.initials: C
authors.lastname: de Loura Santana
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Daniela de Fátima Teixeira
authors.initials: Dde F
authors.lastname: Silva
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Alessandro Melo
authors.initials: AM
authors.lastname: Deana
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Renato Araujo
authors.initials: RA
authors.lastname: Prates
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Amanda Pires
authors.initials: AP
authors.lastname: Souza
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Mariana Teixeira
authors.initials: MT
authors.lastname: Gomes
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Brunna Pileggi
authors.initials: BP
authors.lastname: de Azevedo Sampaio
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Josiane Ferraretto
authors.initials: JF
authors.lastname: Shibuya
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Sandra Kalil
authors.initials: SK
authors.lastname: Bussadori
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Raquel Agnelli
authors.initials: RA
authors.lastname: Mesquita-Ferrari
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Kristianne Porta Santos
authors.initials: KP
authors.lastname: Fernandes
authors.affiliation: Postgraduate Program in Biophotonics Applied to Health Sciences, University Nove de Julho (UNINOVE), São Paulo, São Paulo, Brazil.
authors.forename: Cristiane Miranda
authors.initials: CM
authors.lastname: França
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D003094:Collagen / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental; D004195:Disease Models, Animal; D005260:Female; D006097:Granulation Tissue / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D007249:Inflammation / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D053685:Laser Therapy; D058628:Myofibroblasts / Q000378:metabolism; D020556:Neutrophil Infiltration; D051381:Rats; D014945:Wound Healing; D014947:Wounds and Injuries / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*
chemical_list: D000199:Actins; D003094:Collagen