Targeting of tumor tissues with magnetic nanoparticles

Magnet-enforced targeting of drug-loaded superparamagnetic iron oxide nanoparticles (SPIO-NP) towards malignant tumors appears to be a desirable tool to reduce adverse side effects of systemically applied drugs including biologicals such as specific monoclonal antibodies. In order to make magnetic targeting feasible for tumors in the depth of the body we propose to load red blood cells (RBC) with SPIO-NP and use them as blood-born carriers to target them to endothelial cells of the tumor neo-vasculature. We employ original optoelectronical techniques to monitor the uptake of SPIO-NP. Targeting will be achieved by labeling of RBC with antibodies recognizing receptors specifically expressed by tumor endothelial cells together with strong external magnets placed over tumors. Here, we report magnetic and optoelectronical in vitro experiments showing the feasibility of endothelial cell loading with SPIO-NP, encapsulation of derivatized SPIO-NP in RBC, surface conjugation of RBC with antibodies, their binding to cultured endothelial cells and subsequent internalization.