Use of magnetic resonance targeting to steer ov-loaded cell-based therapies to tumor sites in vivo

Background Despite considerable progress in the development of cellbased therapies, targeted delivery to specific tissues particularly those deep in the body where direct injection is not possible has been problematic. Here we show that tumour-conditioned macrophages infected with oncolytic HSV Seprehvir display a classic activated (M1) profile characterized by the expression of pro-inflammatory factors such as iNOS, IL-6, IL-8 and tumor necrosis factor-a (TNF-a). Furthermore, the M1 macrophages can be magnetically labeled using super-paramagnetic iron oxide nanoparticles (SPIOs) and then steered from the bloodstream into deep target tissues using pulsed magnetic-field gradients inherent to all magnetic resonance imaging systems (MRI). We have called this approach magnetic resonance targeting (MRT) and have used it to deliver a cell-based oncolytic virotherapy.