A novel method to prepare water-dispersible magnetic nanoparticles and their biomedical applications: Magnetic capture probe and specific cellular uptake

A novel and simple method to form water-dispersed magnetic nanoparticles was Successfully developed through glucosaminic acid-surface modification of iron oxide nanoparticles. The resultant glucosaminic acid-modified magnetic nanoparticles (GA-MNP's) had not only good uniformity in spherical shape with diameter of about 1013 nm, but also possessed excellent water-dispersity and stability. In Cell Culture experiments, the internalization of GA-MNPs into different kinds of cells was observed over a 5-day period. The results indicated that the internalization of GA-MNPs into mouse macrophage, cells and mouse embryonic fibroblast cells was not observed after 40 h of Culturing. However, the GA-MNPs were internalized quickly into cancer cells after just 24 h Of Culturing. TEM images of the GA-MNPs uptake in ECA-109 cells were used to study the internalization mechanisms of GA-MNPs and their distribution in ECA-109 cells. Additionally, a water-dispersed magnetic capture probe was prepared by immobilization Of oligonucleotides onto GA-MNPs, and the probe was used for detection and separation of their complementary oligonucleotides sequence. (c) 2008 Wiley Periodicals, Inc.