Photodynamic therapy using chloro-aluminum phthalocyanine decreases inflammatory response in an experimental rat periodontal disease model.

Background and Objective: Emerging evidence suggests that photodynamic therapy (PDT) can exhibit immunomodulatory activity. The purpose of the present study was to analyse cytokine profiles after application of PDT in gingival tissues of rats with ligature-induced periodontal disease (PD).
Study Design/material and Methods: Periodontal disease was induced through the introduction of a cotton thread around the first left mandibular molar, while the right side molars did not receive ligatures. After 7days of PD evolution, ligatures were removed from the left side, and the animals were randomically divided into the following treatment groups: I, rats without treatment; II, rats received chloro-aluminum phthalocyanine (AlClPc); III, rats received low-level laser alone; and IV, rats received AlClPc associated with low-level laser (PDT). The animals were killed 7days after the treatments, and the mandibles were histologically processed to assess morphological and immunohistochemical profile, while gingival tissues were removed for quantification of tumor necrosis factor (TNF)-α, interleukin (IL-)1β and IL-10 expression (by ELISA).
Results: Histomorphological analysis of periodontal tissues demonstrated that PDT-treated animals show tissue necrosis, as well as lower TNF- α expression, compared to ligatured animals treated with AlClPc alone.
Conclusions: It was concluded that PDT using AlClPc entrapped in a lipid nanoemulsion may be useful in therapies, because of immunomodulatory effects that decreased the inflammatory response and cause tissue destruction.
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