Abstract Background Small extracellular vesicles (sEVs) are emerging natural nanoplatforms in cancer diagnosis and therapy, through the incorporation of signal components or drugs in their structure. However, for their translation into the clinical field, there is still a lack of tools that enable a deeper understanding of their in vivo pharmacokinetics or their interactions with the cells of the tumor microenvironment. In this study, we have designed a dual-sEV probe based on radioactive and fluorescent...