Development of Highly Specific Biocompatible Nanoparticles for Differentiation between Cancer and Inflammation using Conventional PET-CT

Functional imaging techniques provide the ability to detect tumors even before structural modifications occur. Positron Emission Tomography (PET) in combination with glucose analogue 18F-2-fluoro-2-deoxy-d-glucose (FDG) is currently the most important functional imaging technique for visualization of tumors by taking advantage of the increased glucose metabolic activity of cancer cells. However, a major shortcoming of this technology is the non-specificity for tumor tissues as other biological events, such as infection or inflammation, which are usually induced by cancer therapy techniques, also result in increased glucose metabolic activity. Since PET scan combined with FDG measures the uptake of glucose, it is inconclusive and does not discriminate between cancer recurrence and post treatment inflammatory conditions. In this research we developed a highly specific, biodegradable nanoparticle for differentiation between cancer and inflammation using conventional PET-CT technique. The lipid- based nanoparticles-liposomes, שרק functionalized with both glucose and a radioactive tracer in order to increase cellular uptake and to enable nanoparticle detection respectively. The liposomes sensitively discriminate between tumors and inflammation due to the unique bio-distribution and pharmacokinetic profile of nanoparticles, along with the unique characteristics of tumor vasculature which allow the accumulation and retention of nanoparticles in a defined size range to a greater extent than in inflammatory lesions. This enables visualizing cancer tissues and metastases even at an early stage of their development, and distinguishing these tissues from other tissues and inflammation. In addition, by modifying the nanoparticles surface with glucose molecules, an enhanced uptake into tumor tissues is facilitated. This unique metabolic imaging approach, inspired by FDG-PET, can provide distinct data on the metabolic activity of the tumor tissue, thereby allowing specific cancer detection and cancer follow-up capabilities that don`t exist today.