MPI-Guided Photothermal Therapy of Prostate Cancer using Stem Cell Delivery of Magnetotheranostic Nanoflowers

Intratumoral nanoparticle (NP) injection is a commonly used for local hyperthermia. A limitation of this delivery route is the limited NP dispersion and retainment within the tumor, with undesired leakage leading to off-target toxicity. By exploiting their inherent tumor tropism, we have used human mesenchymal stem cells (hMSCs) as delivery vehicles for magnetic theranostic gold-iron oxide nanoflowers (GIONF) to improve their overall intratumoral distribution and retention. GIONF-loaded hMSCs exhibited excellent heating properties for laser photothermal therapy and high tracer performance for visualization and quantification by magnetic particle imaging (MPI). In contrast to naked GIONF, GIONF-hMSCs remained within the prostate tumors one week post-injection, with MPI-guided PTT completely ablating tumors without recurrence.