Immunohistochemical assessment of myofibroblasts and lymphoid cells during wound healing in rats subjected to laser photobiomodulation at 660 nm.
OBJECTIVE
The goal of this study was to assess the biomodulatory effect of low-level laser therapy (LLLT) on myofibroblasts and T and B cells during wound healing.


BACKGROUND
Phtotobiomodulation using LLLT has been extensively applied to improve wound healing.


METHODS
Standardized artificial surgical wounds were made on the backs of 24 male rats. Half of them underwent LLLT (20 J/cm(2)) at 660 nm delivered for 7 d. At 8 and 14 d post-surgery the healing wounds were removed and immunohistochemical analysis of myofibroblasts, T cells, and B cells was carried out. The mean of each cell subset was calculated and compared to one another using two-way analysis of variance (ANOVA) and Tukey's test.


RESULTS
The average number of myofibroblasts was statistically significantly higher in the irradiated group than in the non-irradiated group on the eighth (p = 0.001) but not the 14th (p = 0.555) day. B and T cells were significantly more conspicuous in the irradiated group on both the eighth (p = 0.004 and 0.02, respectively) and 14th days (p = 0.04 and 0.03, respectively).


CONCLUSIONS
Our results suggest that LLLT facilitates myofibroblastic differentiation during the early stages of the cicatricial repair process. Furthermore, LLLT also appears to modulate the inflammatory response by downregulating lymphocytic proliferation during the wound healing process.
Ribeiro
Maria Amalia Gonzaga
MA
Propedeutics and Integrated Clinics, Federal University of Bahia, School of Dentistry, Salvador, Bahia, Brazil. endoribeiro@yahoo.com.br
Albuquerque
Ricardo Luiz Cavalcanti
RL
Ramalho
Luciana Maria Pedreira
LM
Pinheiro
Antonio Luiz Barbosa
AL
Bonjardim
Leonardo Rigoldi
LR
Da Cunha
Samantha Seara
SS
D000818:Animals; D002454:Cell Differentiation / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D005347:Fibroblasts / Q000166:cytology / Q000528:radiation effects*; D007150:Immunohistochemistry; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy; D008214:Lymphocytes / Q000528:radiation effects*; D008297:Male; D009130:Muscle, Smooth / Q000166:cytology / Q000528:radiation effects*; D051381:Rats; D017208:Rats, Wistar; D014945:Wound Healing / Q000528:radiation effects*