Early intervention of carbon dioxide fractional laser in hypertrophic scar through TGFβ-1/ Smad3 signaling pathway.

Hypertrophic scars are usually the result of surgical trauma or burn,and more common in individuals with a darker skin color. They appear as red and raised lesions around the wound that continually expand over a period of weeks or months, causing itching, pain, burning sensation and discomfort. Severe scarring affects interpersonal and social relationships, and decreases the quality of life of the patients.The aim of this study was to evaluate the effect of carbon dioxide fractional laser as an early intervention against hypertrophic scars using a rabbit ear scar model, and explore the role of the TGFβ-1/ Smad3 signaling pathway in scar hyperplasia. Four wounds were made into each ear of rabbits, and divided into the untreated control and three laser-treatment groups. The experimental groups received laser intervention once, twice and thrice respectively. laser treatment significantly inhibited the formation of hypertrophic scars, and maximum benefits were seen in the wounds that received three laser treatments. Immunohistochemical staining showed that the in situ expression of TGFβ-1 and Smad3 in the scars decreased by varying degrees after laser intervention, and was most obvious after three laser interventions. Furthermore, the expression levels were the lowest at the end of 6 months after modeling. Therefore, we can assume that early intervention with carbon dioxide fractional laser can prevent formation of hypertrophic scars by regulating the TGF-β1/Smad3 pathway.