title: Use of Spectroscopic Techniques for Evaluating the Coupling of Porphyrins on Biocompatible Nanoparticles. A Potential System for Photodynamics, Theranostics, and Nanodrug Delivery Applications.
abstract: Modern medicine has been searching for new and more efficient strategies for diagnostics and therapeutics applications. Considering this, porphyrin molecules have received great interest for applications in photodiagnostics and phototherapies, even as magnetic nanoparticles for drug-delivery systems and magnetic-hyperthermia therapy. Aiming to obtain a multifunctional system, which combines diagnostics with therapeutic functions on the same platform, the present study employed UV/vis absorption and fluorescence spectroscopies to evaluate the interaction between meso-tetrakis(p-sulfonatofenyl)porphyrin (TPPS) and maghemite nanoparticles (γ-Fe2O3). These spectroscopic techniques allowed us to describe the dynamics of coupling porphyrins on nanoparticles and estimate the number of 21 porphyrins per nanoparticle. Also, the binding parameters, such as the association constants (Ka= 8.89 × 105M-1) and bimolecular quenching rate constant (kq= 2.54 × 1014M-1s-1) were obtained. These results suggest a static quenching process where the electrostatic attraction plays an essential role. The work shows that spectroscopic techniques are powerful tools to evaluate the coupling of organic molecules and nanoparticles. Besides, the system studied provides a relevant background for potential applications in bionanotechnology and nanomedicine, such as (1) nanodrug delivery system, (2) photodiagnostics/theranostics, and/or (3) a combined action of photodynamic and hyperthermia therapies, working in a synergetic way.
authors.affiliation: Instituto de Física and §Programa de Pós-graduação em Química, Universidade Federal de Goiás , 74690-900 Goiânia, GO, Brazil.
authors.forename: Lais N
authors.initials: LN
authors.lastname: Magno
authors.affiliation: Instituto de Física and §Programa de Pós-graduação em Química, Universidade Federal de Goiás , 74690-900 Goiânia, GO, Brazil.
authors.forename: Fábio C
authors.initials: FC
authors.lastname: Bezerra
authors.affiliation: Instituto de Física and §Programa de Pós-graduação em Química, Universidade Federal de Goiás , 74690-900 Goiânia, GO, Brazil.
authors.forename: Luiz Eduardo S
authors.initials: LE
authors.lastname: Freire
authors.affiliation: Instituto de Física and §Programa de Pós-graduação em Química, Universidade Federal de Goiás , 74690-900 Goiânia, GO, Brazil.|Faculdade Santa Rita de Cássia , Av. Adelina Alves Vilela, n° 393, Jd. Primavera, 75.524-680 Itumbiara, GO, Brazil.
authors.forename: Rubens A
authors.initials: RA
authors.lastname: Guerra
authors.affiliation: Instituto de Física and §Programa de Pós-graduação em Química, Universidade Federal de Goiás , 74690-900 Goiânia, GO, Brazil.
authors.forename: Andris F
authors.initials: AF
authors.lastname: Bakuzis
authors.affiliation: Instituto de Física and §Programa de Pós-graduação em Química, Universidade Federal de Goiás , 74690-900 Goiânia, GO, Brazil.
authors.forename: Pablo J
authors.identifier: http://orcid.org/0000-0003-0246-1073
authors.initials: PJ
authors.lastname: Gonçalves
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000528:radiation effects; D004337:Drug Carriers / Q000737:chemistry / Q000528:radiation effects; D005290:Ferric Compounds / Q000737:chemistry* / Q000528:radiation effects; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry / Q000528:radiation effects; D008027:Light; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D017319:Photosensitizing Agents / Q000737:chemistry / Q000528:radiation effects; D011166:Porphyrins / Q000737:chemistry* / Q000528:radiation effects; D000068936:Theranostic Nanomedicine
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D005290:Ferric Compounds; D005456:Fluorescent Dyes; D017319:Photosensitizing Agents; D011166:Porphyrins; C000499:ferric oxide; C016136:tetraphenylporphine sulfonate