A drug's mode of action and efficacy are correlated not only with its ability to accumulate in the targeted pathological tissues, i.e. its tissue bio-distribution, but also with its ability to specifically reach its molecular target within cells. Non-specific accumulation of a drug in these cells can be the cause of undesired effects, such as side effects during chemotherapy. In other words, assessing a drug's efficacy, specificity and absence of toxicity requires precise, quantitative determination of its cellular bio-distribution. Antibody-drug conjugates (ADCs) have become an indispensable tool in oncology, enabling vectorized therapy to preferentially target a subset of tumor cells expressing the antigen recognized by the antibody.

These ADCs target specific tumor cells expressing a particular antigen, thus limiting toxicity to healthy tissue. Radioactive labeling of drugs (3H, 14C) is a key method for quantifying their accumulation in tumor and non-tumor cells, in order to assess targeting accuracy and avoid undesirable side effects. However, the detection of low-level tritium emissions requires new technological solutions. The project proposes the development of an innovative microfluidic platform to detect and quantify these isotopes in single cells. This approach will enable us to better document ADC distribution in heterogeneous tissues and refine therapeutic strategies.