Drug efflux transporters of the ATP-binding-cassette superfamily play a major role in the availability and concentration of drugs at their site of action. ABCC2 (MRP2) and ABCG2 (BCRP) are among the most important drug transporters that determine the pharmacokinetics of many drugs and whose overexpression is associated with cancer chemoresistance. ABCC2 and ABCG2 expression is frequently altered during treatment, thus influencing efficacy and toxicity. Currently, there are no routine approaches available to closely monitor transporter expression. Here, we developed and validated a UPLC-MS/MS method to quantify ABCC2 and ABCG2 in extracellular vesicles (EVs) from cell culture and plasma. In this way, an association between ABCC2 protein levels and transporter activity in HepG2 cells treated with rifampicin and hypericin and their derived EVs was observed. Although ABCG2 was detected in MCF7 cell-derived EVs, the transporter levels in the vesicles did not reflect the expression in the cells. An analysis of plasma EVs from healthy volunteers confirmed, for the first time at the protein level, the presence of both transporters in more than half of the samples. Our findings support the potential of analyzing ABC transporters, and especially ABCC2, in EVs to estimate the transporter expression in HepG2 cells.

Senescence is a dynamic, multifaceted process implicated in tissue aging, organ dysfunction, and intricately associated with numerous chronic diseases. As senescent cells accumulate, they drive inflammation, fibrosis, and metabolic disruption through the senescence-associated secretory phenotype (SASP). Despite its clinical relevance, senescence remains challenging to detect non-invasively due to its heterogeneous nature and the lack of universal biomarkers. Recent advances in the development of specific imaging probes for positron emission tomography (PET) enable in vivo visualization of senescence-associated pathways across key organs, such as the lung, heart, kidney, and metabolic processes. For instance, [¹⁸F]FPyGal, a β-galactosidase-targeted tracer, has demonstrated selective accumulation in senescent cells in both preclinical and early clinical studies, while FAP-targeted radioligands are emerging as tools for imaging fibrotic remodeling in the lung, liver, kidney, and myocardium. This review examines a new generation of PET radioligands targeting hallmark features of senescence, with the potential to track and measure the process, the ability to be translated into clinical interventions for early diagnosis, and longitudinal monitoring of senescence-driven pathologies. By integrating organ-specific imaging biomarkers with molecular insights, PET probes are poised to transform our ability to manage and treat age-related diseases through personalized approaches.

Sustainability in healthcare, particularly Nuclear Medicine, is essential, especially in managing radioactive materials. Traditional centralized production

Background/Objectives: Overactivation of the HGF/c-MET pathway is implicated in various cancers, making its inhibition a promising therapeutic strategy. While several MET-targeting agents are currently approved or in advanced clinical development, patient selection often relies on invasive tissue-based assays. The development of a specific c-MET radioligand for PET imaging and radioligand therapy represents a non-invasive alternative, enabling real-time monitoring of target expression and offering a pathway to personalized treatment. Methods: Radiosynthesis of [⁶⁸Ga]Ga-DOTA-EMP100 was performed using a GMP-certified ⁶⁸Ge/⁶⁸Ga generator connected to an automated synthesis module. The radiopharmaceutical production was optimized by scaling down the amount of DOTA-EMP-100 from 50 to 20 μg. Synthesis efficiency and release criteria were assessed according to Ph. Eur. for all the final products by evaluating radiochemical yield (RY%), radiochemical purity, presence of free gallium (by Radio-UV-HPLC) and gallium colloids (by Radio-TLC), molar activity (Am), chemical purity, pH, and LAL test results. Results: An optimized formulation of [⁶⁸Ga]Ga-DOTA-EMP-100, using 40 μg of precursor, provided the best outcome in terms of radiochemical performance. Process validation across three independent productions confirmed a consistent radiochemical yield of 64.5% ± 0.5, high radiochemical purity (>99.99%), and a molar activity of 53.41 GBq/µmol ± 0.8. Conclusions: [⁶⁸Ga]Ga-DOTA-EMP-100 was successfully synthesized with high purity and reproducibility, supporting its potential for multi-dose application in clinical PET imaging and targeted radioligand therapy.