Objective: A novel pH-sensitive superparamagnetic drug delivery system was developed
based on quercetin loaded hyperbranched polyamidoamine-b-polyethylene glycol-folic acid-modified
Fe3O4 nanoparticles (Fe3O4@PAMAM-b-PEG-FA).
Methods: The nanoparticles exhibit excellent water dispersity with well-defined size distribution
(around 51.8 nm) and strong magnetisability. In vitro release studies demonstrated that the quercetinloaded
Fe3O4@PAMAM-b-PEG-FA nanoparticles are stable at normal physiologic conditions (pH 7.4
and 37°C) but sensitive to acidic conditions (pH 5.6 and 37°C), which led to the rapid release of the
Results: Fluorescent microscopy results indicated that the Fe3O4@PAMAM-b-PEG-FA nanoparticles
could be efficiently accumulated in tumor tissue compared with non-folate conjugated nanoparticles.
Also, in comparison with free quercetin, the quercetin loaded Fe3O4@PAMAM-b-PEG-FA exerts
higher cytotoxicity. Furthermore, this magnetic nanocarrier showed high MRI sensitivity, even in its
lower iron content.
Conclusion: The results indicated that the prepared nanoparticles are an effective chemotherapy and
diagnosis system to inhibit proliferation and monitor the progression of tumor cells, respectively.