Evaluation of the use of low level laser and photosensitizer drugs in healing.
OBJECTIVE
In the last decade, many different kinds of therapies have emerged as a consequence of advances in the field of applied technology. It is known that low level laser therapy contributes to tissue healing; however, the use of photodynamic therapy (PDT) in healing and the scar formation processes has not been fully explored. The present study analyses the effect of low level laser InGaAIP (685 nm), radiation, either alone or combined with a phthalocyanine-derived photosensitizer (PS) in a gel base delivery (GB) system, on the healing process of cutaneous wounds in rats.


METHODS
The rats were divided into six groups: control (untreated) (CG), gel base (GB), photosensitizer (PS), laser (LG), laser+photosensitizer (LPS), and laser+photosensitizer in a GB (LPSG). Standardized circular wounds were made on the dorsum of each rat with a skin punch biopsy instrument. After wounding, treatment was performed once daily and the animals were killed at day 8. Tissue specimens containing the whole wound area were removed and processed for histological analysis using conventional techniques. Serial cross-sections were analyzed to evaluate the organization of the dermis and epidermis as well as collagen deposition.


RESULTS
The animals of groups LG, PS, LPS, and LPSG presented higher collagen content and enhanced re-epithelialization as compared to CG (control) and GB rats. Connective tissue remodeling was more evident in groups LPS and LPSG.


CONCLUSIONS
The results clearly indicated a synergetic effect of light+photosensitizer+delivery drug on tissue healing. PDT did not cause any healing inhibition or tissue damage during the healing process.
Silva
Janine Cuzzolin E
JC
IP&D, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, Urbanova, 12244-000, São Josédos Campos, SP, Brasil.
Lacava
Zulmira Guerrero Marques
ZG
Kuckelhaus
Selma
S
Silva
Luciano Paulino
LP
Neto
Luis Ferreira Monteiro
LF
Sauro
Evandro Emanoel
EE
Tedesco
Antonio Cláudio
AC
D000287:Administration, Topical; D000818:Animals; D005782:Gels; D007211:Indoles / Q000494:pharmacology; D054833:Isoindoles; D028022:Low-Level Light Therapy; D008297:Male; D017319:Photosensitizing Agents / Q000008:administration & dosage*; D020442:Poloxamer / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000293:injuries* / Q000473:pathology; D014945:Wound Healing / Q000187:drug effects / Q000528:radiation effects*
D005782:Gels; D007211:Indoles; D054833:Isoindoles; D017319:Photosensitizing Agents; D020442:Poloxamer; C013647:phthalocyanine