Biomedical Engineering Reference
In-Depth Information
Figure 4.3
Schematic reaction for phosphorylase-catalyzed polymeriza-
tion of glycogen to form hydrogels (a) and photographs of
reaction mixtures before and after hydrogelation (b).
Figure 4.4 shows the stress-strain curves under compression
mode of the glycogen-based hydrogels obtained under the conditions
of various glycogen/Glc-1-P feed ratios: (1)~(5). The condition of (1)
(lower ratio of glycogen to Glc-1-P) gave the elastic gel, but the gels
became stronger and further turned brittle in nature with increasing
the ratios of glycogen to Glc-1-P. The junction zones became
stiffer with increasing the glycogen/Glc-1-P ratio, resulting in the
strengthened gels; however, further increasing the ratio induced the
brittle nature.
The
hydrogels
were
facilely
converted
into
xerogels
by
lyophilization of the hydrogels.
The X-ray diffraction (XRD) profile of the xerogel showed
diffraction peaks at 2
owing to the
crystalline structure of the double helix amylose chains (Fig. 4.5). This
result indicated that the networks in the xerogel were constructed
based on the double helical entanglement of the elongated amylose
q
= 15.3, 17.1, 20.0, and 23.0
°
