[Influence of ALA-PDT on fibroblast cells from hypertrophic scars]

To determine the effect of ALA-PDT on fibroblast cells from hypertrophic scars in vitro, and to identify proper dosage of photosensitizer and energy level of laser light.

Fibroblast cells from hypertrophic scars were cultured in vitro. ALA (5-aminolevulnilic acid) was added into the culture fluid with different concentrations. Then the cultured cells were exposed to He-Ne laser light (PDT) with different energy levels. The cell inhibition rate was measured with CCK-8 method. The expression of PCNA in fibroblast cells was detected after cultured with ALA-PDT, which was selected according to the proper dosage of ALA and laser light from the result of CCK-8.

No obvious inhibition effect was detected with laser light or photosensitizer alone on fibroblast cells from hypertrophic scars. The inhibition effect appeared when ALA and PDT applied simultaneously, and the inhibition rate increased with the dosage of photosensitizer and the energy level of laser light. Maximal inhibition effect reached with 20 J/cm2 laser light exposure and 0.5 mmol/L of ALA, the expression of PCNA of ALA-PDT group is lower than control group in this condition (30.33 +/- 2.08 vs. 78.33 +/- 3.79, P < 0.05).

The inhibition effect of ALA-PDT on fibroblast cells from hypertrophic scars increases with the dosage of photosensitizer and the energy level of He-Ne laser light. The proper dosage of ALA is 0.5 mmol/L along with 20 J/cm2 laser light exposure.