Quantitative Measurement and Prediction of Biophysical Response During Freezing in Tissues

Abstract

Cryopreservation and cryosurgery are important biomedical applications used to selectively preserve or destroy cellular systems through freezing. Studies using cryomicroscopy techniques, which allow the visualization of the freezing process in single cells, have shown that a drop in viability correlates with the extent of two biophysical events during the freezing process: (a) intracellular ice formation and (b) cellular dehydration. These same biophysical events operate in tissue systems; however, the inability to visualize and quantify the dynamics of the freezing process in tissues has hampered direct correlation of these events with freezing-induced changes in viability. This review highlights two new techniques that use freeze substitution and differential scanning calorimetry to provide dynamic freezing data in tissue. Characteristic dimensions and parameters extracted from these new data are then used in a predictive model of biophysical freezing response in several tissues, including liver and tumor. This approach promises to help guide improved design of both cryopreservation and cryosurgical applications of tissue freezing.

Biochemical and molecular studies using human autopsy brain tissue

“…Several approaches to the freezing and thawing of human brain tissue have been outlined Dodd et al 1988;Gleitz et al 1993;Vonsattel et al 1995;Karlsson and Toner 1996;Johnston et al 1997;Bischof 2000;Leal-Klevezas et al 2000). The protocols differ primarily in the rates of freezing and thawing employed and the nature of the cryoprotectant used (Shirakashi and Tanasawa 1998;Eroglu et al 2000;Furuki 2000).…”

Preservation of Embryonic Stem Cells

“…In the equation, L pg and E Lp are two model parameters (constants) that need to be determined a priori using experimental data. Cell dehydration during freezing can be measured using either a specialized cryostage mounted on a light microscope (Diller 2005;Toner et al 1991) or differential scanning calorimetry (Bischof 2000;Devireddy et al 2001;Devireddy et al 1998;Luo et al 2002). Many studies have been performed to determine the two model parameters for various cells, which have been reviewed and tabulated elsewhere (Bischof 2000;Han and Bischof 2004;He and Bischof 2003;Yang et al 2010b).…”

“…Cell dehydration during freezing can be measured using either a specialized cryostage mounted on a light microscope (Diller 2005;Toner et al 1991) or differential scanning calorimetry (Bischof 2000;Devireddy et al 2001;Devireddy et al 1998;Luo et al 2002). Many studies have been performed to determine the two model parameters for various cells, which have been reviewed and tabulated elsewhere (Bischof 2000;Han and Bischof 2004;He and Bischof 2003;Yang et al 2010b). Although cell dehydration and intracellular ice formation (IIF) can be predicted using the above models, a quantitative understanding of the mechanistic link between the two biophysical events and cell injury has not been well established despite some early efforts in this respect as reviewed in (He and Bischof 2003).…”

“…A summary of the major advantages and drawbacks of the two approaches is given in Table 1. Although a low, non-toxic CPA concentration (usually ≤ ~ 1.5 M) is used in slow-freezing, it is always associated with mechanical and physicochemical injury to cells due to ice formation and slow-freezing (usually ≤ 1 o C/min) induced cell dehydration (Bischof 2000;Gao and Critser 2000;Mazur 1984;Toner 1993). The conventional vitrification approach diminishes ice formation altogether to a harmless level (Fahy et al 1987;Fahy et al 1984;Fahy et al 2004b;Rall and Fahy 1985;Wu et al 2007).…”

Modeling Ice Crystal Formation of Water in Biological System

“…One of the most attractive attentions of this issue is about the mechanisms of cell injury induced by freezing in cryobiology [1]. During the past few decades, a series of cryogenic techniques have been developed for clinical applications in cryosurgery and cryopreservation.…”