| 초록 |
γ-camera imaging probes that include tyrosine unit as a radioisotope labeling site were prepared by PEGylation of gold nanoparticles. Folic acid was also introduced onto nanoparticles for tumoral localization by active targeting. γ-camera images were obtained from the PEGylated and folic acid introduced gold nanoparticles which are free from hydrolysis. The results of folic acid conjugated gold nanoparticles detected from the tumor site at 1 hour i.v. injection; however these signals were disappeared within 24 hours. It suggests although gold nanoparticles had a chance to be adsorbed onto cellular membrane by folic acid, their cellular uptake was prevented by charge repulsion. Compared with the results of polymeric nanoparticles based on glycol-chitosan, these phenomena suggest that EPR effect known as simply particle size dependent effect not only depend on particle size, but also is related with various factors, such as cellular affinity and surface charge of nanoparticles |
