Biomedical Engineering Reference
In-Depth Information
Mechanical
properties
PLLA
PDLLA
Time after implantation
Figure 9.3
Schematic graph showing degradation profiles representative of two
example polyesters (PLLA and PDLLA) that degrade by hydrolysis, compared to an
ideal linear degradation profile that might be expected for polymers that degrade
under enzyme degradation/remodelling.
Table 9.2
Selected properties of synthetic, biocompatible and biodegradable
polymers
a
used as biomedical implants.
P3HB
PGA
PDLLA
PLLA
PLGA
PCL
Melting
temperature
(
◦
C)
170-175
225-230
not defined
173-178
not defined
58
Glass transition
temperature
(
◦
C)
-4 to 10
35 to 40
55 to 60
60 to 65
45 to 55
-72
Young's
modulus
(GPa)
1.1-3.5
7-10
1.9-2.4
1.2-3
1.4-2.8
0.4
Water contact
angle (deg.)
70-80
-
60-70
70-80
-
66
Crystallinity
(%)
55-80
55-56
0
37
0
-
Degradation
period
(months)
>
18
6-12
12-16
>
24
1-12
>
24
a
P3HB, poly(3-hydroxybutyrate); PGA, poly(glycolic acid); PDLLA, poly(DL-lactic acid);
PLLA, poly(L-lactic acid); PLGA, poly(lactic-co-glycolide); PCL, poly(
ε
-caprolactone).
