Gallic Acid–Triethylene Glycol Aptadendrimers Synthesis, Biophysical Characterization and Cellular Evaluation
André Miranda,
Roi Lopez-Blanco,
Jéssica Lopes-Nunes,
Ana M. Melo,
Maria Paula Cabral Campello,
António Paulo,
Maria Cristina Oliveira,
Jean-Louis Mergny,
Paula A. Oliveira,
Eduardo Fernandez-Megia,
Carla Cruz
Affiliations
André Miranda
CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, 6201-506 Covilhã, Portugal
Roi Lopez-Blanco
Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Jenaro de la Fuente s/n, 15782 Santiago de Compostela, Spain
Jéssica Lopes-Nunes
CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, 6201-506 Covilhã, Portugal
Ana M. Melo
iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
Maria Paula Cabral Campello
Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela, Portugal
António Paulo
Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela, Portugal
Maria Cristina Oliveira
Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066 Bobadela, Portugal
Jean-Louis Mergny
Laboratoire d’Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
Paula A. Oliveira
Centre for Research and Technology of Agro-Environmental and Biological Sciences (CITAB), Inov4Agro, University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal
Eduardo Fernandez-Megia
Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Jenaro de la Fuente s/n, 15782 Santiago de Compostela, Spain
Carla Cruz
CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, 6201-506 Covilhã, Portugal
Herein, we describe the synthesis of an aptadendrimer by covalent bioconjugation of a gallic acid–triethylene glycol (GATG) dendrimer with the G-quadruplex (G4) AT11 aptamer (a modified version of AS1411) at the surface. We evaluated the loading and interaction of an acridine orange ligand, termed C8, that acts as an anticancer drug and binder/stabilizer of the G4 structure of AT11. Dynamic light scattering experiments demonstrated that the aptadendrimer was approximately 3.1 nm in diameter. Both steady-state and time-resolved fluorescence anisotropy evidenced the interaction between the aptadendrimer and C8. Additionally, we demonstrated that the iodine atom of the C8 ligand acts as an effective intramolecular quencher in solution, while upon complexation with the aptadendrimer, it adopts a more extended conformation. Docking studies support this conclusion. Release experiments show a delivery of C8 after 4 h. The aptadendrimers tend to localize in the cytoplasm of various cell lines studied as demonstrated by confocal microscopy. The internalization of the aptadendrimers is not nucleolin-mediated or by passive diffusion, but via endocytosis. MTT studies with prostate cancer cells and non-malignant cells evidenced high cytotoxicity mainly due to the C8 ligand. The rapid internalization of the aptadendrimers and the fluorescence properties make them attractive for the development of potential nanocarriers.