title: Effect of photodynamic therapy on the healing of cutaneous third-degree-burn: histological study in rats.
abstract: The aim of this study was to conduct a histological assessment of the effect of photodynamic therapy (PDT) on the repairing of third-degree-burn wounds made on the backs of rats with a heated scalpel. Ninety-six rats were divided into groups: G1, control (n = 24), cold scalpel; G2, burned, heated scalpel (n = 24); G3, low-level laser therapy (LLLT) (n = 24), on burns; and G4, photodynamic therapy (PDT) (n = 24), toluidine-O blue (100 microg/ml) and LLLT treatment on burns. The laser (685 nm) was applied in continuous mode, 50 mW, 4.5 J/cm(2), contact mode at nine points (9 s/point). Eight animals in each group were killed at 3 days, 7 days or 14 days after surgery, and tissue specimens containing the whole wounded area were removed and processed for histological analysis; the results were statistically analyzed with Kruskal-Wallis and Dunn's tests (P < 0.05). The results demonstrated significant differences between G2 and G3, and between G2 and G4, at both 3 days and 7 days, with regard to acute inflammation scores; G1 and G2 showed significant differences when compared with G4 at 3 days, with regard to neo-angiogenesis scores; G1 and G2 were statistically different from G3 and G4 at both 3 days and 7 days, with regard to re-epithelization scores; G2 showed statistically significant differences when compared with G3 and G4 with regard to collagen fiber scores at 7 days. LLLT and PDT acted as a biostimulating coadjuvant agent, balancing the undesirable effect of the burn on the wound healing process, acting mainly in the early healing stages, hastening inflammation and increasing collagen deposition.
authors.affiliation: Study and Research Group in Lasers in Dentistry, Araçatuba School of Dentistry, São Paulo State University (UNESP), Rua José Bonifácio, 1193, 16015-500 Araçatuba, São Paulo, Brazil. vgouveia@foa.unesp.br
authors.forename: Valdir Gouveia
authors.initials: VG
authors.lastname: Garcia
authors.forename: Marcos Alcântara
authors.initials: MA
authors.lastname: de Lima
authors.forename: Tetuo
authors.initials: T
authors.lastname: Okamoto
authors.forename: Luís Alberto
authors.initials: LA
authors.lastname: Milanezi
authors.forename: Erivan Clementino Gualberto
authors.initials: EC
authors.lastname: Júnior
authors.forename: Leandro Araújo
authors.initials: LA
authors.lastname: Fernandes
authors.forename: Juliano Milanezi
authors.initials: JM
authors.lastname: de Almeida
authors.forename: Letícia Helena
authors.initials: LH
authors.lastname: Theodoro
mesh_terms: D000818:Animals; D002056:Burns / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy; D028022:Low-Level Light Therapy; D008297:Male; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D014048:Tolonium Chloride / Q000627:therapeutic use; D014945:Wound Healing / Q000187:drug effects* / Q000528:radiation effects
chemical_list: D017319:Photosensitizing Agents; D014048:Tolonium Chloride