Synthesis and cellular internalization of spindle hematite/polymer hybrid nanoparticles.

Nonspherical spindle-shaped hematite/polymer hybrid nanoparticles (SPNPs) were synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP). The long axis of the SPNPs was 370 ± 65 nm, and the short axis was 80 ± 15 nm with an aspect ratio of 4.6-4.7. The SPNPs were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). Thermogravimetric analysis (TGA) was used to estimate the content of grafted polymer. Light-scattering measurement was used to detect the particle size distribution of SPNPs in water and in cell culture medium. HeLa cells internalized the SPNPs within 1 h, and the uptake reached equilibrium in 8 h. These observations contribute to better understanding of the interactions between nonspherical nanoparticles and cells, which may have implication for designing drug delivery vehicles.