PEG-modified GoldMag nanoparticles (PGMNs) combined with the magnetic field for local drug delivery.

Polyethylene glycol-modified GoldMag nanoparticles (PGMNs) were synthesized and characterized by several analysis including transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectroscopy, and vibrating sample magnetometer. Here, we showed that the composite nanoparticles have a saturated magnetization of 34 emu/g with an average diameter of 50 nm. The kinetics analysis showed the maximum doxorubicin (DOX) loading capacity of PGMNs is 107.78 mg/g. The PGMNs loaded with DOX (DOX-loaded PGMNs) exhibited a controlled drug release pattern within the first 4 h and then a slowly, sustained release pattern for 4 days. The biodistribution of DOX-loaded PGMNs in vivo indicated that the concentrations of DOX in liver exposed to magnetic field group (60.7 ± 8.14, 53.6 ± 4.89, 44.8 ± 6.41, and 38.4 ± 2.58 ng/g) were significantly higher than those of no applied magnetic field group (40.8 ± 9.96, 31.9 ± 7.01, 28 ± 6.11, and 20.7 ± 5.78 ng/g) at 0.5, 1, 2, and 4 h (P < 0.05), respectively. The amount of Fe in liver exposed magnetic field showed a similar trend. Histological studies revealed an enhanced particle aggregation in the targeted liver area. Under the external magnetic field, the biodistribution of DOX-loaded PGMNs was changed compared to absence of magnet field, and the PGMNs were capable of carrying drug for targeting therapeutic purposes.