cooled at a rate of 1
C per min and warmed at a rate of 2
C per
min during the DSC measurement. The solidification temperature
of the solid tissue matrix domain with unfrozen water is measured
to be À44
C, and the T
0
g of the freeze-concentrated amorphous
protectant domain is À18
C. To ensure good structural protection
of the tissue matrix during freezing–drying and the ability of its
rapid rehydration before the clinical application, one may need to
develop a multistep temperature–pressure ramping protocol starting from the lowest solidification temperature.
An example for measuring T e of the liquid solution within
porcine dermis is given in Fig. 7. The porcine dermis sample is
soaked in phosphate-buffered saline. Upon cooling at 0.5
C per
min to À50
C, the salt in the sample precipitates around À22 and
À30
C, and a single eutectic melting is observed upon warming
around À22
C (T e ).
4.3 Vitrification (T g )
and Devitrification (T d )
of Cryopreservation
Solutions
Vitrification is widely used in cell and tissue preservation since it was
introduced into cryopreservation of mammalian cells by Rall and
Fahy [4] and for plant cells and tissues by Uragami et al. [5] and
Sakai et al. [6]. Vitrification methods have the advantage over
traditional slow freezing cryopreservation methods because they
avoid damaging ice crystal formation. By studying vitrification
and devitrification behavior, DSC analysis is used to optimize the
cryoprotectant formulations for ice-free cryopreservation and to
determine the critical cooling and warming rates for vitrification
applications.
Fig. 6 The warming thermogram of the decellularized human tendon tissue after incubation in the 10%
maltodextrin solution. There are two glass transition-like events. The solidification temperature of the solid
tissue matrix domain with unfrozen water is measured to be À44
C, and the T
0
g of the freeze concentrate of
10% maltodextrin (M180) solution in the tissue’s interstitial space is À18
C
DSC Analysis of Thermophysical Properties
295
C per min and warmed at a rate of 2
C per
min during the DSC measurement. The solidification temperature
of the solid tissue matrix domain with unfrozen water is measured
to be À44
C, and the T
0
g of the freeze-concentrated amorphous
protectant domain is À18
C. To ensure good structural protection
of the tissue matrix during freezing–drying and the ability of its
rapid rehydration before the clinical application, one may need to
develop a multistep temperature–pressure ramping protocol starting from the lowest solidification temperature.
An example for measuring T e of the liquid solution within
porcine dermis is given in Fig. 7. The porcine dermis sample is
soaked in phosphate-buffered saline. Upon cooling at 0.5
C per
min to À50
C, the salt in the sample precipitates around À22 and
À30
C, and a single eutectic melting is observed upon warming
around À22
C (T e ).
4.3 Vitrification (T g )
and Devitrification (T d )
of Cryopreservation
Solutions
Vitrification is widely used in cell and tissue preservation since it was
introduced into cryopreservation of mammalian cells by Rall and
Fahy [4] and for plant cells and tissues by Uragami et al. [5] and
Sakai et al. [6]. Vitrification methods have the advantage over
traditional slow freezing cryopreservation methods because they
avoid damaging ice crystal formation. By studying vitrification
and devitrification behavior, DSC analysis is used to optimize the
cryoprotectant formulations for ice-free cryopreservation and to
determine the critical cooling and warming rates for vitrification
applications.
Fig. 6 The warming thermogram of the decellularized human tendon tissue after incubation in the 10%
maltodextrin solution. There are two glass transition-like events. The solidification temperature of the solid
tissue matrix domain with unfrozen water is measured to be À44
C, and the T
0
g of the freeze concentrate of
10% maltodextrin (M180) solution in the tissue’s interstitial space is À18
C
DSC Analysis of Thermophysical Properties
295