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: Valdir Gouveia Garcia, Marcos Alcântara de Lima, Tetuo Okamoto, Luís Alberto Milanezi, Erivan Clementino Gualberto Júnior, Leandro Araújo Fernandes, Juliano Milanezi de Almeida, Letícia Helena Theodoro
• Journal: Lasers in medical science (Lasers Med Sci) Vol. 25 Issue 2 Pg. 221-8 (Mar 2010) ISSN: 1435-604X [Electronic] England
• PMID: 19533211 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Photosensitizing Agents
• Tolonium Chloride

Topics

• Animals
• Burns (drug therapy, pathology, radiotherapy)
• Low-Level Light Therapy
• Male
• Photochemotherapy
• Photosensitizing Agents (therapeutic use)
• Rats
• Rats, Wistar
• Tolonium Chloride (therapeutic use)
• Wound Healing (drug effects, radiation effects)