Assessment of the cryoprotectant concentration inside a bulky organ for cryopreservation using X-ray computed tomography

Cryoprotection of bulky organs is crucial for their storage and for subsequent transplantation. In this work we demonstrate the capability of the X-ray computed tomography (CT) as a non-invasive method to measure the cryoprotectant (cpa) concentration inside a tissue or an organ, specifically for the case of dymethil sulfoxide (Me2SO). It is remarkable that the use of Me2SO has been leader in techniques of cells and tissues cryopreservation. Although CT technologies are mainly based in density differences, and many cpas are alcohols with densities similar to water, the use of very low energies as acceleration voltage (∼70 kV) and the sulfur atom in the molecule of Me2SO makes possible the visualization of this cpa inside tissues. As result we obtain a CT signal proportional to the Me2SO concentration with a spatial resolution up to 50 μm in the case of our device.