Studies on tumor imaging by gallium-68 labeled, nanosized, PEGcoated, tumor targeted liposomes

Diagnosis of the tumor before the cellular changes begin and when changes begin to occur at the molecular level ensures that the treatment is started before the cancer spreads, thus increasing the success rate in the treatment of cancer significantly. Therefore, nowadays, molecular imaging; has become increasingly important. PET, which is one of the methods used in cancer diagnosis and imaging, is a radionuclidic imaging method that is becoming increasingly common today and its use in clinics is increasing accordingly. Gallium-68 (Ga-68) was chosen among the positron emitting radionuclides commonly used in PET. Liposomes, which are used as drug delivery systems, can deliver drugs and/or imaging compounds to the tissue/organ with both passive and active targeting methods. In vitro cell culture studies showed that folate-modified liposomes dispersions have higher uptake in both HeLa and HT-29 tumor cells. In radiolabeling studies radiochemical purity was found around 85% for Ga-68 labeling. In the biodistribution results, it was found that tumor uptake of folate modified liposome dispersions was 2 times higher at 30th min and 2,5 times higher at 60th min than that of unmodified liposomes. However, clear visualization of the tumor could not be achieved in PET imaging studies. Further studies are needed both to increase the marking efficiency and to improve the PET images.