Use of X-Ray Computed Tomography for Monitoring Tissue Permeation Processes.

Cryoprotectants are essential to prevent ice formation during tissue cryopreservation procedures. However, the control of their concentration and spatial distribution in the tissue is necessary to avoid toxicity and other damages associated with the cryopreservation procedures, especially for bulky samples such as tissues and organs. X-ray computed tomography measures the attenuation of an X-ray beam when it passes through a substance, depending on the material properties of the samples. The high electronic density of the sulfur atom of the dimethyl sulfoxide makes it an excellent cryoprotectant to be assessed by X-ray CT, and its concentration is proportional to the X-ray attenuation either at room or cryogenic temperatures. In addition, this imaging technique also allows to detect the formation of ice and eventual fractures within tissues during the cooling and warming processes. Therefore, X-ray CT technology is an excellent tool to assess and develop new cryopreservation procedures for tissues and organs.