Abstract: The uptake of silica nanoparticles(SiNPs) with positive surface charge and negative surface charge by HepG cells, MCF-7 cells and L-02 cells were investigated by using the RITC doped in SiNPs as a synchronous fluorescent signal indicator. The experimental results show that the uptake of SiNPs by the three kinds of cells were all a concentration-, charge-, time-, and serum-dependent endocytic process. To the same kind of SiNPs, the uptake by the three kinds of cells all enhanced with increasing of the SiNPs concentration and incubation timeand gradually reached saturation. However, the effect of serum was different to the uptake of SiNPs with different surface charge. The results display that serum existed in culture medium decreased the cellular uptake of NSiNPs. Whilethe serum existed in culture medium would not affect the cellular uptake of PSiNPs. These results provide a theoretical foundation for the further modification of SiNPs, which could improve the stability of SiNPs in the medium and made it be well applied to biomedicine.

Key words: Silica nanoparticles(SiNPs), Surface charge, Cellular uptake