Combining magnetic nanoparticles with cell derived microvesicles for drug loading and targeting.

Inspired by microvesicle-mediated intercellular communication, we propose a hybrid vector for magnetic drug delivery. It consists of macrophage-derived microvesicles engineered to enclose different therapeutic agents together with iron oxide nanoparticles. Here, we investigated in vitro how magnetic nanoparticles may influence the vector effectiveness in terms of drug uptake and targeting. Human macrophages were loaded with iron oxide nanoparticles and different therapeutic agents: a chemotherapeutic agent (doxorubicin), tissue-plasminogen activator (t-PA) and two photosensitizers (disulfonated tetraphenyl chlorin-TPCS2a and 5,10,15,20-tetra(m-hydroxyphenyl)chlorin-mTHPC). The hybrid cell microvesicles were magnetically responsive, readily manipulated by magnetic forces and MRI-detectable. Using photosensitizer-loaded vesicles, we showed that the uptake of microvesicles by cancer cells could be kinetically modulated and spatially controlled under magnetic field and that cancer cell death was enhanced by the magnetic targeting. From the clinical editor: In this article, the authors devised a biogenic method using macrophages to produce microvesicles containing both iron oxide and chemotherapeutic agents. They showed that the microvesicles could be manipulated by magnetic force for targeting and subsequent delivery of the drug payload against cancer cells. This smart method could provide a novel way for future fight against cancer.