Abstract
PURPOSE: Nanovesicles composed of the phospholipid dioleylphosphatidylserine (DOPS) and a fusogenic protein, saposin C (SapC), selectively target and induce apoptotic cell death in a variety of human cancer cells in vitro and in vivo. We tested whether such tumor-homing nanovesicles are capable of delivering fluorescent probes and magnetic resonance (MR) contrast agents to cancerous tissue to aid in earlier detection and improve visualization. PROCEDURES: SapC-DOPS nanovesicles labeled with either a far-red fluorescent probe (CellVue® Maroon, CVM) or conjugated with a dextran coated MR contrast agent, ultrasmall superparamagnetic iron oxide (USPIO), were systemically administrated into xenografts for tumor detection using optical and MR imaging systems. RESULTS: SapC-DOPS nanovesicles were effectively detected in vivo in tumor-bearing animals using both optical and MR imaging techniques, thereby demonstrating the cancer-selective properties of these nanovesicles. CONCLUSIONS: SapC-DOPS nanovesicles offer promise as a new and robust theranostic agent for broad cancer-selective detection, visualization, and potential therapy.