Biomodulative effects of visible and IR laser light on the healing of cutaneous wounds of nourished and undernourished Wistar rats.
OBJECTIVE
We evaluated histologically the differences in the healing of cutaneous wounds on nourished or undernourished rats following laser phototherapy (LPT) (20 or 40 J/cm2).


BACKGROUND
Wound healing occurs due to a competitive mechanism between the synthesis and lysis of collagen. Any factor that increases the lysis or reduces the synthesis of collagen may change the healing process. Nutritional deficiencies have a great effect on wound healing.


METHODS
Fifty nourished or undernourished Wistar rats had one standardized wound created on the dorsum and were divided into 10 subgroups: Control (standard diet); Control [Northeastern Brazilian basic diet (DBR)]; Standard diet+LPT (lambda635 nm; spatial average energy fluence (SAEF) 20 J/cm2); Standard diet+LPT (lambda635 nm; SAEF 40 J/cm2); Standard diet+LPT (lambda780 nm; SAEF 20 J/cm2); Standard diet+LPT (lambda780 nm; SAEF 40 J/cm2); DBR+LPT (lambda635 nm; SAEF 20 J/cm2); DBR+LPT (lambda635 nm; SAEF 40 J/cm2); DBR+LPT (lambda780 nm; SAEF 20 J/cm2); DBR+LPT (lambda780 nm; SAEF 40 J/cm2). The first application of the treatment was carried out immediately and repeated daily for seven days. The specimens were routinely processed to wax, cut, stained with H&E and Sirius Red stains, and analyzed using light microscopy. The analyses included re-epithelization, inflammatory infiltrate, and fibroblastic proliferation. Sirius Red stained slides were used to perform descriptive analyses of the collagen fibers.


RESULTS
The results showed that LPT with lambda635 wavelength was more effective for the treatment of undernourished subjects, treated with either LPT with lambda730 nm with SAEF of 20 J/cm2 or lambda780 nm with SAEF of 40 J/cm2.


CONCLUSIONS
Nutritional status influenced the progression of the healing process as well as the quality of the healed tissue. In addition, the use of both wavelengths resulted in a positive biomodulatory effect on both nourished and undernourished subjects.
Pinheiro
Antonio Luiz Barbosa
AL
Laser Center, Department of Propedeutica and Clinical Integrada, School of Dentistry, Federal University of Bahia, Salvador, BA, Brazil. albp@ufba.br
Meireles
Gyselle Cynthia Silva
GC
Carvalho
Carolina Montagn
CM
Ramalho
Luciana Maria Pedreira
LM
dos Santos
Jean Nunes
JN
D000818:Animals; D053685:Laser Therapy / Q000379:methods; D044342:Malnutrition / Q000503:physiopathology*; D009752:Nutritional Status; D010784:Photomicrography; D010789:Phototherapy / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000293:injuries* / Q000528:radiation effects; D013194:Staining and Labeling; D014945:Wound Healing / Q000528:radiation effects*