Chapter 12
Use of X-Ray Computed Tomography for Monitoring Tissue
Permeation Processes
Ariadna Corral, Alberto Olmo, and Ramo ´ n Risco
Abstract
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.
Key words Tissue permeation, X-ray computed tomography, Tissue and organ cryopreservation,
Cryoprotectant concentration assessment, Ice formation, Tissue fractures formation
1 Introduction
Whereas a wide variety of cell types can be cryopreserved, either by
the traditional slow freezing protocol or by vitrification, the creation of a biobank for tissues is still a challenge. The larger volume
and complexity of tissues and organs imply heat and mass limitations during cryopreservation procedures making them more likely
to be damaged by ice, cryoprotectant toxicity, and fractures during
the cooling and warming processes. Therefore, cryopreservation of
large samples requires accurate control of temperature and cryoprotective agent (CPA) concentration. We have established the use
of X-ray computed tomography technology to noninvasively monitor cryopreservation protocols and assess CPA concentration for
the particular case of dimethyl sulfoxide at lower acceleration voltage (65–75 kV) [1].
Willem F. Wolkers and Harrie ¨ tte Oldenhof (eds.), Cryopreservation and Freeze-Drying Protocols, Methods in Molecular Biology,
vol. 2180, https://doi.org/10.1007/978-1-0716-0783-1_12, © Springer Science+Business Media, LLC, part of Springer Nature 2021
317
Use of X-Ray Computed Tomography for Monitoring Tissue
Permeation Processes
Ariadna Corral, Alberto Olmo, and Ramo ´ n Risco
Abstract
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.
Key words Tissue permeation, X-ray computed tomography, Tissue and organ cryopreservation,
Cryoprotectant concentration assessment, Ice formation, Tissue fractures formation
1 Introduction
Whereas a wide variety of cell types can be cryopreserved, either by
the traditional slow freezing protocol or by vitrification, the creation of a biobank for tissues is still a challenge. The larger volume
and complexity of tissues and organs imply heat and mass limitations during cryopreservation procedures making them more likely
to be damaged by ice, cryoprotectant toxicity, and fractures during
the cooling and warming processes. Therefore, cryopreservation of
large samples requires accurate control of temperature and cryoprotective agent (CPA) concentration. We have established the use
of X-ray computed tomography technology to noninvasively monitor cryopreservation protocols and assess CPA concentration for
the particular case of dimethyl sulfoxide at lower acceleration voltage (65–75 kV) [1].
Willem F. Wolkers and Harrie ¨ tte Oldenhof (eds.), Cryopreservation and Freeze-Drying Protocols, Methods in Molecular Biology,
vol. 2180, https://doi.org/10.1007/978-1-0716-0783-1_12, © Springer Science+Business Media, LLC, part of Springer Nature 2021
317