RESUMO
Folate receptor (FR) is particularly upregulated in many epithelial cancer cells membrane and limited distribution is found in normal tissues. In the present work, the folic acid protected gold nanoparticles (FA-GNPs) were synthesized by a simple and quick method, in which chloroauric acid (HAuCl4) was reduced by sodium borohydride (NaBH4) in the presence of FA is used as stabilizer. UV-Visible spectroscopy and transmission electron microscopy (TEM) were used to characterize the shape and size distribution of the produced FA-GNPs. X-ray photoelectron spectroscopy and cell experiment were employed to confirm the immobilization of FA and GNPs. The results showed that FA-GNPs have a good size distribution in the 3-5 nm diameter range. Moreover, it is very stable even in solution with high concentration of salt (up to 3.5% NaCl), and even high speed centrifuges of 25 000 r x min(-1) could not cause aggregation. The nanoparticles could be used to detect cancer cells.
Assuntos
Receptores de Folato com Âncoras de GPI/metabolismo , Ácido Fólico/química , Ouro/química , Nanopartículas Metálicas/química , Espectroscopia Fotoeletrônica/métodos , Linhagem Celular Tumoral , Humanos , Análise Espectral/métodosRESUMO
A novel strategy by means of poly diallyl dimethylammonium chloride (PDDA) was used to make highly mono-dispersed positively charged gold nanoparticles, and 5-ALA was immobilized onto the gold nanoparticles through electrostatic interaction. The conjugation of 5-aminolevulinic acid (5-ALA) and gold nanopartilces were characterized by the integrated tools of resonance Rayleigh scattering (RRS), UV-Vis absorption spectra, transmission electron microscopy (TEM) and laser light scattering. The results demonstrated that 5-ALA can be attached onto positively charged gold nanoparticles. This new photosensitizer is significant for enhancing PDT efficacy clinically.