title: Synthesis and characterization of gold nanostructured Chorin e6 for Photodynamic Therapy.
abstract: Photodynamic therapy is an alternative treatment for cancer based on cellular uptake of a photosensitizer, illuminated with an appropriate wavelength in the presence of oxygen. A cascade of reactions generates reactive oxygen species leading to cell death. Using carbodiimide chemistry, chlorin e6 (Ce6) was covalently bonded to thiourea, and (via the sulphur end group) to gold nanoparticles (AuNPs), forming the Ce6-AuNP complex. Ce6 absorbs in the range 650-680nm, where the coefficient of biological tissue absorption is low (part of the therapeutic window), which is ideal for biological application. Transmission Electron Microscopy, UV-vis spectroscopy, Fourier transform Infrared Spectroscopy and Zeta potential measurements were completed to characterize the Ce6-AuNP complex. The bare AuNPs have an average diameter of 18±4nm. A line of human breast carcinoma cells (MDA-MB-468) was used to determine whether Ce6 functionalization to AuNPs potentiate its activity. Trypan blue assays were used to assess cell viability. In the absence of light, Ce6 either alone or bounded to AuNPs was not cytotoxic. When irradiated at 660nm, the cytotoxicity of Ce6-AuNP was higher than Ce6 alone for MDA-MB-468 cells using 4h incubation. AuNPs without Ce6 showed no cytotoxic.
authors.affiliation: Laboratório de Nanossensores, Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, São José dos Campos, São Paulo, 12244-000, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Vieira
authors.affiliation: Laboratório de Nanossensores, Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, São José dos Campos, São Paulo, 12244-000, Brazil.
authors.forename: M L
authors.initials: ML
authors.lastname: Castilho
authors.affiliation: Laboratório de Nanossensores, Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, São José dos Campos, São Paulo, 12244-000, Brazil.
authors.forename: I
authors.initials: I
authors.lastname: Ferreira
authors.affiliation: Laboratório de Nanossensores, Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, São José dos Campos, São Paulo, 12244-000, Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Ferreira-Strixino
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, Halifax, Nova Scotia, B3H 4R2, Canada.
authors.forename: K C
authors.initials: KC
authors.lastname: Hewitt
authors.affiliation: Laboratório de Nanossensores, Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911, São José dos Campos, São Paulo, 12244-000, Brazil. Electronic address: lraniero@univap.br.
authors.forename: L
authors.initials: L
authors.lastname: Raniero
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002735:Chlorophyllides; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D006046:Gold / Q000737:chemistry* / Q000627:therapeutic use*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry / Q000627:therapeutic use*; D009374:Neoplasms, Experimental / Q000188:drug therapy* / Q000473:pathology; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000138:chemical synthesis; D011166:Porphyrins / Q000008:administration & dosage* / Q000737:chemistry*; D016896:Treatment Outcome
chemical_list: D002735:Chlorophyllides; D017319:Photosensitizing Agents; D011166:Porphyrins; C062985:phytochlorin; D006046:Gold
keywords: Breast cancer; Chlorin e6; Gold nanoparticles; Photodynamic therapy