5 research outputs found
Remote Actuation of Magnetic Nanoparticles For Cancer Cell Selective Treatment Through Cytoskeletal Disruption
Motion of micron and sub-micron size magnetic particles in alternating magnetic fields can activate mechanosensitive cellular functions or physically destruct cancer cells. However, such effects are usually observed with relatively large magnetic particles (>250 nm) that would be difficult if at all possible to deliver to remote sites in the body to treat disease. Here we show a completely new mechanism of selective toxicity of superparamagnetic nanoparticles (SMNP) of 7 to 8 nm in diameter to cancer cells. These particles are coated by block copolymers, which facilitates their entry into the cells and clustering in the lysosomes, where they are then magneto-mechanically actuated by remotely applied alternating current (AC) magnetic fields of very low frequency (50 Hz). Such fields and treatments are safe for surrounding tissues but produce cytoskeletal disruption and subsequent death of cancer cells while leaving healthy cells intact
Luteinizing Hormone Releasing Hormone-Targeted Cisplatin-Loaded Magnetite Nanoclusters for Simultaneous MR Imaging and Chemotherapy of Ovarian Cancer
Given the superior
soft tissue contrasts obtained by MRI and the
long residence times of magnetic nanoparticles (MNPs) in soft tissues,
MNP-based theranostic systems are being developed for simultaneous
imaging and treatment. However, development of such theranostic nanoformulations
presents significant challenges of balancing the therapeutic and diagnostic
functionalities in order to achieve optimum effect from both. Here
we developed a simple theranostic nanoformulation based on magnetic
nanoclusters (MNCs) stabilized by a bisphosphonate-modified polyÂ(glutamic
acid)-<i>b</i>-(ethylene glycol) block copolymer and complexed
with cisplatin. The MNCs were decorated with luteinizing hormone releasing
hormone (LHRH) to target LHRH receptors (LHRHr) overexpressed in ovarian
cancer cells. The targeted MNCs significantly improved the uptake
of the drug in cancer cells and decreased its IC<sub>50</sub> compared
to the nontargeted formulations. Also, the enhanced LHRHr-mediated
uptake of the targeted MNCs resulted in enhancement in the T<sub>2</sub>-weighted negative contrast in cellular phantom gels. Taken together,
the LHRH-conjugated MNCs show good potential as ovarian cancer theranostics