Photosensitizers and Exposure Times To Light Showed Tissue Compatibility In Isogenic Mice

Objective: The aim of this study was to evaluate the subcutaneous tissue response after different protocols to photodynamic therapy (PDT). In Phase 1, were tested the diode laser (used for 1min) associated to the photosensitizer phenothiazine chloride solution (PCS) in different concentrations. In Phase 2 – the diode laser and LED were tested associated to two different photosensitizers, PCS and Curcumin, in different exposure times of light application. Material and Methods: After 7, 21 and 63-days the animals were euthanized and the subcutaneous tissue processed to histological analysis. Qualitative and semi-quantitative descriptions of the inflammatory process and immunohistochemical technique were performed. The obtained data were analyzed by Kruskal-Wallis and Dunn’s post-test (alpha = 0.5). Results: On Phase 1, the tissue response was very similar among the groups. For the inflammatory infiltrate, PCS with concentration of 10mg/mL exhibited the most intense reaction (p > 0.05). On Phase 2, at 7-days period, the analyzed parameters presented small magnitude and after 21 and 63-days, all the parameters demonstrated tissue compatibility. Conclusion: Both photosensitizers presented proper tissue compatibility regardless the different concentrations used on Phase 1 and different durations of light exposure on Phase 2.   Keywords Photodynamic therapy; Phenothiazine chloride solution; Curcumin; Isogenic mice; Subcutaneous tissue.