title: Evaluation of vascular effect of Photodynamic Therapy in chorioallantoic membrane using different photosensitizers.
abstract: Photodynamic Therapy (PDT) is a local treatment that requires a photosensitizing agent, light and molecular oxygen. With appropriate illumination, the photosensitizer is excited and produces singlet oxygen that is highly reactive and cytotoxic. Tumor vascular network is essential for the tumor growth and the understanding of vascular response mechanisms enables an improvement in the PDT protocol for cancer treatment. Compounds of porphyrin (Photogem®) and chlorin (Photodithazine®) were the photosensitizers tested. The incubation times varied from 20 to 80 min and the concentration ranged between 0.1 and 100 μg/cm(2). Different light doses were used between 4.8 and 40 J/cm(2) with irradiance varying between 80 and 100 mW/cm(2). The light dose of 30 J/cm(2) was used in the intravenous photosensitizer application. The membrane images were made from 0 to 300 min after treatment. The vascular response was evaluated by the average vessel area. Different responses was observed depending on the photosensitizer concentration and administration form. Intravenous application has been more efficient to produce vessel constriction and the most pronounced effect was observed for the chlorin.
authors.affiliation: São Carlos Institute of Physics, University of São Paulo, Avenida Trabalhador São Carlense, 400, CEP: 13566-590, Caixa Postal: 369, São Carlos, SP, Brazil. Electronic address: hilde.buzza@usp.br.
authors.forename: H H
authors.initials: HH
authors.lastname: Buzzá
authors.affiliation: São Carlos Institute of Physics, University of São Paulo, Avenida Trabalhador São Carlense, 400, CEP: 13566-590, Caixa Postal: 369, São Carlos, SP, Brazil.
authors.forename: L V
authors.initials: LV
authors.lastname: Silva
authors.affiliation: São Carlos Institute of Physics, University of São Paulo, Avenida Trabalhador São Carlense, 400, CEP: 13566-590, Caixa Postal: 369, São Carlos, SP, Brazil.
authors.forename: L T
authors.initials: LT
authors.lastname: Moriyama
authors.affiliation: São Carlos Institute of Physics, University of São Paulo, Avenida Trabalhador São Carlense, 400, CEP: 13566-590, Caixa Postal: 369, São Carlos, SP, Brazil.
authors.forename: V S
authors.initials: VS
authors.lastname: Bagnato
authors.affiliation: São Carlos Institute of Physics, University of São Paulo, Avenida Trabalhador São Carlense, 400, CEP: 13566-590, Caixa Postal: 369, São Carlos, SP, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: Kurachi
mesh_terms: D000287:Administration, Topical; D000818:Animals; D002645:Chickens; D049033:Chorioallantoic Membrane / Q000187:drug effects* / Q000528:radiation effects; D007275:Injections, Intravenous; D008027:Light; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D011166:Porphyrins / Q000737:chemistry / Q000494:pharmacology; D013997:Time Factors
chemical_list: D017319:Photosensitizing Agents; D011166:Porphyrins; C006969:chlorin
keywords: CAM; Chorioallantoic membrane; PDT; Photodynamic Therapy; Vascular effect