RESUMO
Gold nanoparticles (Au NPs) are promising vectors for gene delivery applications. In order to gain insight on the influence of particle size on cell transfection, Au NPs were combined with poly(ethylenimine) (PEI) to prepare two sets of PEI-coated Au NPs having particle-size distributions centered at about 6 nm (<10nm Au-PEI NPs) or 70 nm (<100 nm Au-PEI NPs), respectively. Au-PEI NPs were coupled to a variety of plasmids carrying reporter or suicide genes to prepare Au-PEI NPs/DNA complexes, and human osteosarcoma Saos-2 cells were used to investigate the performance of the Au-PEI NPs as transfection vectors in serum-containing media. The conjugates of DNA with both types of Au-PEI NPs were found to be negatively charged. In spite of the electrostatic repulsion that occurs between the surface of the cell and the surface of the plasmid-conjugated NPs, cell internalization was observed for both kinds of Au-PEI NPs. Cells were efficiently transfected with complexes derived from <10 nm Au-PEI NPs, but not with the <100 nm Au-PEI NPs. Large aggregates of NPs associated with DNA were found in endocytic vesicles of cells incubated with <100 nm Au-PEI NPs, while the success of the smaller Au-PEI NPs as transfection vectors was related to their lower agglomeration state inside cells and to endosomal escape of DNA.
Assuntos
Ouro/química , Nanopartículas Metálicas/química , Tamanho da Partícula , Polietilenoimina/química , Transfecção/métodos , Materiais Biocompatíveis/farmacologia , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , DNA/metabolismo , Endocitose/efeitos dos fármacos , Endossomos/efeitos dos fármacos , Endossomos/metabolismo , Humanos , Teste de Materiais , Nanopartículas Metálicas/ultraestrutura , Plasmídeos/metabolismo , Eletricidade Estática , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismoRESUMO
The ability of core/shell SiO(2)/Au nanoparticles (NPs) to heat upon being exposed to near-infrared (NIR) radiation is well known. In this work we have modified the synthesis procedure to obtain a mesoporous SiO(2) core and a porous Au shell that allows drugs to be loaded within the core porous space. The release of a model drug (ibuprofen) upon NIR activation is demonstrated.
Assuntos
Preparações de Ação Retardada/química , Ouro/química , Ibuprofeno/administração & dosagem , Nanopartículas/química , Dióxido de Silício/química , Raios Infravermelhos , Lasers , Nanopartículas/ultraestrutura , PorosidadeRESUMO
Inorganic nanoparticles (NPs) show great potential for medicinal therapy. However, biocompatibility studies are essential to determine if they are safe. Here, five different NPs are compared for their cytotoxicity, internalization, aggregation in medium, and reactive oxygen species (ROS) production, using tumoral and normal human blood cells. Differences depending on the cell type are analyzed, and no direct correlation between ROS production and cell toxicity is found. Results are discussed with the aim of standardizing the procedures for the evaluation of the toxicity.