Photodynamic Therapy of Cancer Cells with Methanesulfonate Salts of 5-Aminolevulinic Acid and Its Derivatives

A series of 5-aminolevulinic acid and its alkylester methanesulfonates was exploited to photodynamic therapy（PDT） of human lymphocytic cells, U-937 in vitro. The PDT efficiency is influenced by the concentration and incubation time. Generally, for ALA and its alkylester methanesulfonates, the cell survival rate decreases and the accumulation ability of PplX increases with the concentration and incubation time. We found that the longer carbon chain methanesulfonates（C5-S, C6-S, C8-S） exhibit better PDT effect than ALA methanesulfonate. This possibly provides a promising route to the clinical application ofPplX-mediated PDT to cancer cell.