Multifunctional ferromagnetic nanodiamond for dual-mode fluorescence imaging and magnetic drug targeting

The use of nanoparticles as drug delivery vehicles has been receiving much attention in recent years, especially for cancer treatment, with high hope to develop nanocarriers that can deliver therapeutic compounds to the target sites more efficiently. Magnetic drug targeting can be an effective way to deliver drugs to specific areas controlled by magnetic fields at the tumor area; possible to guide and transport anticancer drugs bound to magnetic materials to the tumor site. In this study, magnetic nanodiamond (MND) particles are used as an efficient drug delivery vehicle which can be targeted and imaged simultaneously. A protein Human serum albumin (HSA) is conjugated to MND to improve dispersion in biological medium and to facilitate controlled release of the drug. The particle loaded with clinical drug doxorubicin (DOX) and the effectiveness of the therapy against the cancer cells in-vitro was studied. The DOX-loaded MNDa-HSA remained stable for a prolonged period, rendering its ability to penetrate and release its drug into cells. When nanodiamond-DOX complexes are exposed to magnetic field (MF), their IC50 values are reduced significantly lower than those of free DOX and MNDa-HSA-DOX (without MF). The results indicate that MNDa-HSA could be a potential carrier for vectoring drugs using an external magnetic field, also enabling to be used as a biolabeling agent which can be tracked using fluorescence imaging.