RESUMEN
BACKGROUND: Nonablative laser has been used for the treatment and prevention of skin aging for many years. Although the mechanism has not been elucidated, histological evaluation showed that the dermal fibroblasts and its collagen production should be the main target for this rejuvenation. In order to determine the effects of a 1320 nm nonablative laser on the human dermal fibroblasts, the two main secretion factors, basic fibroblast growth factor (bFGF) and transforming growth factor ß1(TGF-ß1), in vitro were detected. METHODS: The human dermal fibroblasts were cultured and irradiated with a 1320 nm laser at the dose of 15, 20, and 24 J/cm(2) respectively. The number of fibroblasts was counted and the levels of bFGF and TGF-ß1 were detected by enzyme-linked immunosorbent assay at the time points of 0, 24, 48, and 72 h after irradiation. RESULTS: The results showed that both the number of fibroblasts and the secretion of bFGF increased after the irradiation at the dose of 20 and 24 J/cm(2) (P<0.05) compared with that of the control cells. The bFGF secretion in the group exposed to 20 J/cm(2) was more significant than that of 24 J/cm(2), and the peak level was 24 h after irradiation. The level of TGF-ß1 secretion decreased after irradiation in a dose-dependent manner (15 and 20 J/cm(2), both P<0.05; 24 J/cm(2), P<0.01), and reached a nadir at 24 h. CONCLUSION: Our results suggested that the 1320 nm nonablative laser accelerates the vitality of fibroblasts, promotes the secretion of bFGF, and inhibits TGF-ß1 secretion by fibroblasts.