Development of red-luminescent hybrids as contrast agents for cell imaging: A correlation among surface, luminescence, and biological properties

Autor(es)

Santos, Joao Antonio Oliveira ; Brito, Lorrane Davi ; da Costa, Paulo Inacio ; Pires, Ana Maria ; Lima, Sergio Antonio Marques

• Tipo de documento: Artigo Científico
• Fonte: Optical Materials; v. 139, p. 14-pg., 2023-04-13.

Resumo

TTA (2-thenoyltrifluoroacetone), DBM (dibenzoylmethane), and EPHEN (5,6-Epoxy-5,6-dihydro- [1,10] phenanthroline) have generated europium complexes with excellent red emission properties. However, for bio applications, these complexes have been grafted on the surface of silica nanoparticles (SNP), by different approaches, due to their low water solubility. Here, we report how three approaches influence the surface, luminescent, and biological properties of 50 and 170 nm-SNP functionalized with carboxylic acid or phenanthroline ligands, useful to anchor TTA and DBM-Eu-complexes. TTA-hybrids exhibited better photophysical properties over the DBM ones, although intermolecular interactions between TTA and silica surface groups are likely to influence their properties. Aiming at such biological application, approach 3 resulted in the luminescent PHEN-hybrids with the highest values of intrinsic (phi EuEu) and absolute quantum yields (phi LEu), color purity of 100%, and high sensibilization efficiency (eta). However, depending on the approach used, different surface charges were observed for the hybrids that directly impacted their cytotoxicity in Huh 7.5 cells. The larger the size of the nanoparticle or the more positive its surface charge is, the lower the toxicity of the hybrid. Even considering the presence of the protein corona effect, estimated in DMEM medium, the initial surface charge, observed in the buffer solution, plays an important role in the nanoparticle-cell interaction. Confocal microscopy images revealed that the hybrids were internalized by cells regardless of their size and surface charge, and their luminescence was also detectable, making them promising candidates for cell imaging applications as luminescent contrast agents. (AU)

• Processo FAPESP: 19/26103-7 - Partículas de sílica decoradas com complexos luminescentes para aplicação em sensoriamento e imageamento celular
• Beneficiário: Sergio Antonio Marques de Lima
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50945-4 - INCT 2014: Instituto Nacional de Tecnologias Alternativas para Detecção, Avaliação Toxicológica e Remoção de Micropoluentes e Radioativos
• Beneficiário: Maria Valnice Boldrin
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/04907-3 - Nanopartículas de sílica funcionalizadas com base de Schiff
• Beneficiário: João Antonio Oliveira Santos
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica