Effect of photodynamic therapy on the healing of cutaneous third-degree-burn: histological study in rats.
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.
Garcia
Valdir Gouveia
VG
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
de Lima
Marcos Alcântara
MA
Okamoto
Tetuo
T
Milanezi
Luís Alberto
LA
Júnior
Erivan Clementino Gualberto
EC
Fernandes
Leandro Araújo
LA
de Almeida
Juliano Milanezi
JM
Theodoro
Letícia Helena
LH
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
D017319:Photosensitizing Agents; D014048:Tolonium Chloride