Novel inorganic nanoplatelets for drug delivery in cancer nanotherapy

The lack of selectivity and sufficient delivery of the current anticancer agents in use is a major cause of severe side effects and treatment failures. Our approach is to use zirconium hydrogen phosphate (ZrP) nanoplatelet, an inorganic layered nanoparticle, for targeted delivery of anticancer drugs to cancer cells and control release of drugs inside the cells in response to the acidic pH inside the cancer cells. ZrP can be prepared in the 50-150 nm size range with platelet-like shape. The platelet shape is particularly important for nanoparticles to deliver anticancer drugs to tumors as it can overcome some of the disadvantages of spherically shaped nanoparticles for margination, penetration through vascular fenestrations and adherence to endothelial walls. ZrP are themselves non-toxic to human cells and can intercalate high load of many different anti-cancer drugs between their layers by ion-exchange, swelling the layers, or exfoliation. We have illustrated this assertion by placing high levels of doxorubicin (DOX) within the layers. Our in-vitro studies with doxorubicin loaded ZrP (DOX:ZrP) nanoplatelets in breast cancer cell line (MCF-7) showed approximately 50-fold kill of cells after 48 hours after incubation with DOX:ZrP, compared with only doxorubicin. Confocal microscopy studies showed that DOX:ZrP nanoparticles are taken up rapidly by the cells. The control cells treated with pure doxorubicin solution, most of the drug was expelled as shown by its presence on the periphery of the cells. The complete synthesis, characterization and biological assays performed for these materials will be presented.