Better understanding on stem cell tracking is required before regenerative medicines therapies (RMTs) can be used. However, there is not a single molecular imaging technology capable of providing the breadth of information required. For instance, while MRI offers excellent spatial resolution, sensitivity is low, whereas for SPECT/PET, the converse is true.In this context, the combination of nanotechnology and new imaging techniques such as photoacoustic imaging (PAI) emerge as potential disruptive technology. Biocompatible nanoprobes can be rationally designed to label specific cell without interfering with biological parameters such as differentiation or metabolic processes but improving the contrast of the imaging technique. Gold nanorods and more complex structures such as hollow nanoparticle or hybrids show special optical properties that enable their use as contrast agents for PAI achieving then enough sensitivity to monitor single cells. Moreover, these optical properties are easily tunable and can be adjusted to perform a multiple real time labelling thanks to the rapid acquisition and the extremely high resolution of PAI. Thus, the combination of these two technologies together will provide a non-invasive, long term, in vivo cell tracking of stem cell in models of kidney injury already developed and validated. Thus, the amelioration of fibrosis and the recovery of renal function amongst other will be assessed together with the safety studies that will include biodistribution, tumourigenesis, inflammation, systemic toxicity, etc. All together will contribute to establish efficacy and safety of RMTs.