Novel nanoparticles can deliver anticancer drugs into cells.

Researchers have designed a novel graft polymer shell for iron oxide nanoparticles, which can deliver anticancer drugs and realize real-time monitoring of drug release.

　　Recently, chemists at the University of New South Wales (UNSW) in Australia have synthesized a new type of iron oxide nanoparticles, which can not only deliver anticancer drugs to cells, but also monitor the release of drugs in real time. Researchers say this is an important progress in the field of nano-diagnosis and treatment. Related papers were published in ACS Nano, a journal of American Chemical Society recently.

　　"This kind of iron oxide nanoparticles can track and monitor drug delivery, which makes it possible to adapt to the individual differences of different patients." Cyril Boya, an associate professor at UNSW School of Chemical Engineering, said. Knowing how the anticancer drug delivered by nanoparticles is released and its influence on cells and surrounding tissues, doctors can adjust the dosage to achieve the best curative effect of the drug.

　　For a long time, magnetic iron oxide nanoparticles (IONPs) have been widely studied, but most of them are used as contrast agents in magnetic resonance imaging (MRI). Only recently have they been explored for drug delivery. At present, only a few studies have described how to load chemotherapy drugs on the surface of magnetic iron oxide nanoparticles, which can not effectively prove that they can really deliver drugs into cells, just some speculations. In this study, a new method was designed to load drugs on the surface of IONPs, and it was proved for the first time that these particles could deliver drugs into cells.

　　UNSW researchers fitted IONPs with a well-designed graft polymer shell, which made it show excellent colloidal stability in water and serum. Polymer shell can realize the reversible adhesion of doxorubicin (an anti-tumor drug) through imine bond, which provides a controllable release mechanism for doxorubicin in acidic environment.

　　Using a technique called Fluorescence Lifetime Imaging Microscopy (FLIM), researchers proved for the first time that IONPs can be easily accepted by two cell lines (MCF-7 breast cancer cells and H1299 lung cancer cells), and at the same time, the release of DOX in cells can be monitored.

　　"Usually, drug release experiments are only simulated in the laboratory, not in cells. This is very important. With cells, we can determine the dynamic movement of drug release in a real biological environment. " Boya said, "We have proved that workbench chemistry (referring to traditional chemical experiments without high-end equipment and computer models) can also be carried out in cells, and the next step is to enter the living application."