Biomedical Engineering Reference
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fiber. Amide hydrolysis was found from TEM investigations to occur
near the overlap and gap zones.
Pederson and Ruberti
43
reported a strategy for exploiting tem-
perature driven self-assembly of collagen and thermally triggered
liposome mineralizationto form amineralized collagen composite.
Zhang
et al
. have also synthetically prepared nano-fibrils of
mineralized collagen as a self-assembly model system, with the
objectiveofevaluatingthepossibilityofsynthesizingmaterialswith
hierarchicalstructuressimilartothosefoundinnature(Fig.37.2).
44
Firstly, they prepared solutions containing collagen, calcium and
phosphate ions following a processing route described by Bradt
et al
.
45
and then changed either pH or temperature to induce the
formation of collagen fibrils. TEM investigations of unstained sam-
ples at low magnification revealed that the composites formed con-
sist of an intertwined assembly of collagen fibrils bundles more
than 1
μ
m long (Fig. 37.2a). Each collagen fibril is surrounded by a
Figure 37.2.
TEM image and HRTEM image of mineralized collagen
fibrils.
44
(a)TEMimage:Theinsertisaselectedareaelectrondiffractionpat-
tern of the mineralized collagen fibrils. (b) HRTEM image: The long arrow
indicates the longitudinal direction of the collagen fibrils. The two short
arrowsindicatetwoHAnanocrystals.
Abbreviation
:HRTEM,high-resolution
transmission electron microscopy.
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