Iron oxide/PLGA nanoparticles for magnetically controlled drug release

Recently, nanoscale stimuli-responsive devices have received much
attention thanks to their potential to limit the cytotoxic effect of the therapeutic
treatment at the diseased tissue. Among different physical triggers, large
alternating magnetic fields enable the conversion of magnetic energy into
heat by using magnetic nanoparticles that generate localized hyperthermia,
named Magneto Fluid Hyperthermia (MFH). This methodology can be exploited
for cancer therapy or/and thermally activated drug release. The small size
iron oxide nanoparticles (Fe-NPs), such as SPIO (small iron oxide particles)
and USPIO (ultra-small iron oxide particles), currently used for this
application have many limitations due to their 1) high intratumor
concentration needed due to the low heating power 2) short particle
blood-half-life, 3) non-specific distribution, 4) low internalization
efficiency. For these reasons many efforts are necessary to make magneto
fluid particle hyperthermia (MFH) a competitive tumor therapy for clinical
applications. New iron oxide nanoparticles, coated with oleate, with a
diameter of 5-18 nm, have been prepared by co-precipitation and incorporated
into PLGA-NPs (PLGA=Poly(lactic-co-glycolic acid) in order to improve their
biocompatibility and ``in vivo'' stability. Moreover, PLGA-NPs have been
loaded with both NPs-Fe and antitumor drugs (Paclitaxel, PTX), an anticancer
hydrophobic drug used in the treatment of ovarian and breast cancer, to
perform MFH triggered drug release. The PTX and Fe-NPs loaded nanoparticles
may be considered as an effective anticancer drug delivery system for
Imaging-guided hyperthermic treatment of tumors.