Effects of photodynamic therapy mediated by nanoemulsion containing chloro-aluminum phthalocyanine: a histologic and immunohistochemical study in human gingiva.

Background: Photodynamic therapy (PDT) uses photosensitizing agents, which are delivered in target cells, followed by local application of visible light in specific wavelengths. This reaction produce reactive oxygen species able to induce cell death by apoptosis or necrosis, injured to the local vasculature, and exert important effects on the immune system.
Objective: The present work evaluated the clinical findings, histomorphological alterations and immunodetection of VEGF after PDT using chloro-aluminum phthalocyanine (AlClPc) entrapped in a lipid nanoemulsion in a split-mouth clinical trial.
Material and Methods: Eight healthy volunteers with clinical indication for extraction were included in the study. Seven days before the extraction 40 ul of nanoemulsion AlClPc 5μM was injected into gingival tissue followed by irradiation with diode laser, the contralateral side was used as control. Tissue specimens were removed seven days after the PDT and divided into two groups (test and control groups) for histological and immunohistochemical analysis. Patients were monitored at days, 0, 7, 14 and 30 to assess adverse effects of the therapy.
Results: The therapy was well tolerated by all patients. Adverse effects were short-time and completely reversible. Areas of edema, vascular congestion, and intense vascularization were viewed in gingival samples that received PDT. Additionally, dystrophic calcification was observed in subepithelial region. VEGF showed moderate to strong immunostaining in specimens subjected to PDT.
Conclusions: Taken together, the results showed that the protocol used in this study mediated by nanoemulsion containing AlClPc is safe for clinical application in gingival tissue and suggests that VEGF is increased after PDT.
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