5-Aminolevulinic Acid-Mediated Photodynamic Therapy of Human Endometriotic Primary Epithelial Cells

Objective: Despite progress in medicine, appropriate diagnosis and treatment of endometriosis poses a serious problem. For this reason, in in-vitro experiments were performed on a potential method of employing photodynamic therapy (PDT) of endometriosis using 5-aminolevulinic acid (ALA). Background Data: The exogenous application of ALA induces the accumulation of protoporphyrin IX, a natural and effective photosensitizer used in photodynamic diagnosis and therapy. Materials and Methods: To this end primary epithelial cells were isolated from endometriotic foci, preincubated with various ALA concentrations, and then exposed to light energy (a bulb or laser) for 8 min; 24 and 48 h later cell lesions were evaluated using fluorescent staining. Results: When bulb illumination was used, after 48 h cells were found that had disturbed chromatin concentration and fragmentation. Illumination with a laser beam resulted in strong induction of apoptosis 24 h post-exposure. With both types of illumination the number of necrotic cells was insignificant. Staining with rhodamine 123 demonstrated the presence within the endometriotic foci of epithelial cells that were resistant to ALA-induced photodynamic therapy. Conclusion: The effects of PDT on primary epithelial endometriotic cells may prove useful in designing a phototherapeutic procedure for the detection and treatment of endometriosis.