[(18)F]-Fluorinated Carboplatin and [(111)In]-Liposome for Image-Guided Drug Delivery

Radiolabeled liposomes have been employed as diagnostic tools to monitor in vivo distribution of liposomes in real-time, which helps in optimizing the therapeutic efficacy of the liposomal drug delivery. This work utilizes the platform of [(111)In]-Liposome as a drug delivery vehicle, encapsulating a novel (18)F-labeled carboplatin drug derivative ([(18)F]-FCP) as a dual-molecular imaging tool as both a radiolabeled drug and radiolabeled carrier. The approach has the potential for clinical translation in individual patients using a dual modal approach of clinically-relevant radionuclides of (18)F positron emission tomography (PET) and (111)In single photon emission computed tomography (SPECT). [(111)In]-Liposome was synthesized and evaluated in vivo by biodistribution and SPECT imaging. The [(18)F]-FCP encapsulated [(111)In]-Liposome nano-construct was investigated, in vivo, using an optimized dual-tracer PET and SPECT imaging in a nude mouse. The biodistribution data and SPECT imaging showed spleen and liver uptake of [(111)In]-Liposome and the subsequent clearance of activity with time. Dual-modality imaging of [(18)F]-FCP encapsulated [(111)In]-Liposome showed significant uptake in liver and spleen in both PET and SPECT images. Qualitative analysis of SPECT images and quantitative analysis of PET images showed the same pattern of activity during the imaging period and demonstrated the feasibility of dual-tracer imaging of a single dual-labeled nano-construct.