Biomedical Engineering Reference
In-Depth Information
TABLE 2.1
Collected Arrhenius Parameters for Example Thermal Damage Process
Process Parameters
Process
A
(s
−1
)
E
a
(J mole
−1
)
T
Tcrit
(°C)
Notes
Cell Death
Sapareto
(32)
2.84 × 10
99
6.18 × 10
5
51.4
CHO Cells,
T
> 43°C
Beckham
(34)
6.9 × 10
116
7.3 × 10
5
53.2
Murine w/o Hsp70
3.7 × 10
157
9.8 × 10
5
51.7
Murine w/Hsp70
Bhowmick
(9)
7.78 × 10
22
1.61 × 10
5
94.2
H. Prostate apoptosis/necrosis
Bhowmick
(44)
1.66 × 10
91
5.68 × 10
5
52.1
AT-1 Cells < 50°C
173.5
1.97 × 10
4
186
AT-1 Cells > 50°C
Borrelli
(35)
2.984 × 10
80
5.064 × 10
5
55.5
BhK Cells
He
(40)
4.362 × 10
43
2.875 × 10
5
71.0
SN12 cells, suspended
3.153 × 10
47
3.149 × 10
5
73.1
SN12 cells, attached
Erythrocytes
Lepock
(37)
7.6 × 10
66
4.55 × 10
5
82.2
Hemoglobin denaturation
Przybylska
(36)
a
1.08 × 10
44
2.908 × 10
5
71.8
Hemolysis, Normal RBCs
a
3.7 × 10
43
2.88 × 10
5
72.1
Hemolysis, Down syndrome RBCs
Skin Burns
Henriques
(22)
59.9
Not recommended
3.1 × 10
98
6.28 × 10
5
Diller
(45)
58.6
8.82 × 10
94
6.03 × 10
5
T
≤
5
3°C (same data)
69.3
1.297 × 10
31
2.04 × 10
5
T
> 53°C
We a v e r
(41)
55.4
2.19 × 10
124
7.82 × 10
5
T
≤ 50°C
1.82 × 10
51
3.27 × 10
5
60.1
T
> 50°C
Brown
(39)
1.98 × 10
106
6.67 × 10
5
54.6
Microvessels in muscle
Retinal Damage
We l c h
(46)
3.1 × 10
99
6.28 × 10
5
56.6
Whitening
Collagen Changes
Maitland
(47)
1.77 × 10
56
3.676 × 10
5
68.2
Rat tail birefringence
Pearce
(48)
1.61 × 10
45
3.06 × 10
5
80.4
Rat skin birefringence
Aksan
(49)
1.136 × 10
86
5.623 × 10
5
68.1
Rabbit patellar tendon
Miles
(50)
6.658 × 10
79
5.21 × 10
5
67.8
Rat tail tendon, DSC
Chen
(51-53)
1.46 × 10
66
4.428 × 10
5
76.4
Shrinkage, rat tail tendon
Muscle
Jacques
(54)
2.94 × 10
39
2.596 × 10
5
70.4
Myocardium whitening
Liver
Jacques
(55)
5.51 × 10
41
2.769 × 10
5
73.4
Whitening, pig liver
a
Value for
A
is estimated from Wright's line.
usually accompanies cell death. The transition zone contains tis-
sues that may regenerate postheating.
(5)
and swells in diameter in an approximately isovolumic process
as the macromolecules unwind. As the temperature increases,
the collagen assumes an amorphous glassy, or hyalinized, state.
The completely denatured collagen is resorbed during healing
and eventually replaced by scar tissue.
(4,5)
Elastin is a thermally robust structural tissue protein respon-
sible for the elasticity of large arteries and other mechanical
energy-storing structures, such as the
ligamentum nuchae
in
the necks of grazing animals. Elastin is thermally stable until
temperatures exceed the boiling point. Tissue fusion processes
rely on the complete denaturation of collagen and also elastin,
if present.
2.2.2.2 Structural protein Denaturation
Collagen is the ubiquitous basic structural protein for almost all
tissues, an especially prominent feature of blood vessels, con-
nective tissues such as tendons and ligaments, and bone. There
are at least 13 various forms of the collagen molecule.
(18)
Heating
collagen results in unraveling of the rope-like molecular and
macromolecular structure that is the source of its strength and
resilience. At higher temperatures collagen shrinks in length
