Background: A promising approach to optimize the disposition of daunorubicin-loaded magnetic nanoparticles (DNR-MNPs) was developed to minimize serious side effects of systematic chemotherapy for cancer.
Methods: The physical properties of DNR-MNPs were investigated and their effect on leukemia cells in vitro was evaluated by a standard WST-1 cell proliferation assay. Furthermore, cell apoptosis and intracellular accumulation of DNR were determined by FACSCalibur flow cytometry.
Results: Our results showed that the majority of MNPs were spherical and their sizes were from 10 to 20 nm. The average hydrodynamic diameter of DNR-MNPs in water was 94 nm. The in vitro release data showed that the DNR-MNPs have excellent sustained release property. Proliferation of K562 cells was inhibited in a dose-dependent manner by DNR in solution (DNR-Sol) or by DNR-MNPs. The IC(50) for DNR-MNPs was slightly higher than that for DNR-Sol. DNR-MNPs also induced less apoptosis in K562 cells than did DNR-Sol. Detection of fluorescence intensity of intracellular DNR demonstrated that DNR-MNPs could be taken up by K562 cells and persistently released DNR in cells.
Conclusion: Our study suggests that optimized DNR-MNPs formulation possesses sustained drug-release and favorable antitumor properties, which may be used as a conventional dosage form for antitumor therapy.
Keywords: K562 cells; daunorubicin; drug delivery system; magnetic iron oxide nanoparticles; target selection.