Acta Pharmacologica Sinica (2009) 30: 1688–1693; doi: 10.1038/aps.2009.158

Aim: MgFe₂O₄ magnetic nanoparticle composed of As₂O₃ (As₂O₃-MNPs) were prepared and their in vitro and in vivo characteristics were studied.

Methods: The solvent-displacement method was applied for preparation of the nanoparticle using Poly-D,L-lactic-co-glycolic acid(PLGA).  The characteristics studies of the products included magnetic response, morphology (transmission electron microscopy and scanning electron microscopy), entrapment efficiency, drug loading, particle sizes, zeta potential, in vitro drug release and tissue magnetic targeting.  Nanoparticle cytotoxicity to Saos-2 cells was investigated using the MTT assay.  To guide the external magnetic field in the liver, the concentration of As₂O₃ in the liver and kidney was measured using an atomic fluorescence spectrometer after injecting As₂O₃-MNPs into the caudal veins of mice. 

Results: The As₂O₃-MNPs were approximately spherical.  The average diameter, drug loading, entrapment efficiency and zeta potential of As₂O₃-MNPs were 109.9 nm, 10.08%, 82.16%, and -14.33 mV, respectively.  The specific saturation magnetism was 8.65 emu/g.  In vivo, the concentration of As₂O₃ in the liver was significantly higher than that in the non-magnetic group. While the concentration of As₂O₃ in the kidney was lower than that in the non-magnetic group.  The C_max in liver tissue in the magnetic group was 30.65 μg/g, which was 4.17 times the drug concentration in the same group in kidney tissue (7.35 μg/g) and 2.88 times the concentration of drug (10.66 μg/g) in the liver tissue of the non-magnetic group.

Conclusion: The PLGA polymer-loaded magnetic nanoparticle composed of arsenic trioxide can be magnetically targeted well and applied in biomedicine.

Keywords: As₂O₃; PLGA; magnetic nanoparticle; Mg-Fe ferrite; targeting