An in vitro study on the photosensitivity of 5-aminolevulinic acid conjugated gold nanoparticles.

Background: In this study, the photosensitivity of 5-aminolevulinic acid (5-ALA) conjugated gold nanoparticles (conjugate) has been investigated on the MeL-Rm cell line.

Methods: After culture and proliferation of the Mel-Rm cell line, cell toxicity and the suitable cell incubation time of the conjugate were determined. Photosensitivity of the conjugate and free 5-ALA was then studied in optical doses of 20, 40, 60 and 80 J/cm(2) while light irradiation was applied by a He-Ne laser.

Results: A 4-h time interval was determined as the optimum incubation time for 5-ALA and the conjugate. PpIX induction into the cells showed a significant increase after incubation with the conjugate in comparison to 5-ALA alone. Also, the conjugate resulted in a two times higher cell death rate compared to free 5-ALA.

Conclusions: The conjugate can be used as an appropriate delivery agent for 5-ALA and provide efficient cell destruction during PDT.