Whole-body tracking of single cells via positron emission tomography
Menée à l'aide d'un modèle murin et de cellules de cancer du sein d'origine humaine, cette étude met en évidence l'intérêt de nanoparticules de silice mésoporeuses concentrant le gallium 68 pour suivre, à l'aide d'une tomographie par émission de positrons, le trajet de cellules isolées et déterminer avec précision leur distribution dans l'organisme
In vivo molecular imaging can measure the average kinetics and movement routes of injected cells through the body. However, owing to non-specific accumulation of the contrast agent and its efflux from the cells, most of these imaging methods inaccurately estimate the distribution of the cells. Here, we show that single human breast cancer cells loaded with mesoporous silica nanoparticles concentrating the 68Ga radioisotope and injected into immunodeficient mice can be tracked in real time from the pattern of annihilation photons detected using positron emission tomography, with respect to anatomical landmarks derived from X-ray computed tomography. The cells travelled at an average velocity of 50 mm s−1 and arrested in the lungs 2–3 s after tail-vein injection into the mice, which is consistent with the blood-flow rate. Single-cell tracking could be used to determine the kinetics of cell trafficking and arrest during the earliest phase of the metastatic cascade, the trafficking of immune cells during cancer immunotherapy and the distribution of cells after transplantation.
Nature Biomedical Engineering , résumé, 2020