Effects of surface functional groups on the aggregation stability of magnetite nanoparticles in biological media containing serum

Abstract

-Size stability of magnetite nanoparticles (MNP) with different surface functional groups in biological media was achieved by the addition of fetal bovine serum (FBS). The stability of the particles was attributed to the formation of protein coronas around the particles, which provides sufficient steric hindrance to prevent aggregation of the particles. The stability of different modified MNP were also studied in biological media containing bovine serum albumin (BSA) to further understand the stabilization mechanism. BSA was found to stabilize polyethyleneimine (PEI) modified MNP and polymethacrylic acid (PMAA) coated MNP, but not the bare MNP. These results indicate a difference in interactions between serum protein and the MNP that is govern by the type of functional groups on the MNP surface, with positively charged surface groups resulting higher protein adsorption and better stability.

Cytotoxicity of InP/ZnS Quantum Dots With Different Surface Functional Groups Toward Two Lung-Derived Cell Lines

“…Here, our data showed that InP/ZnS coated with hydroxyl group were more likely to aggregate, and the particle size in the water was far greater than the other QDs coated with carboxyl or amino group. It is mainly because that the hydroxyl groups around the particles couldn’t provide sufficient steric hindrance to counterbalance the attractive Van der Waal forces between particles ( Wiogo et al, 2011 ). Apart from the stability and hydrodynamic size distribution, the surface properties also influence the fluorescence intensity of the QDs.…”