Biomedical Engineering Reference
In-Depth Information
(a)
(b)
Figure 9.2
Schematics of polymer-matrix composite structures containing ceramic
or glass reinforcement: (a) oriented glass-ceramic fibres and (b) glass-ceramic particles
dispersed in the polymer matrix. For a better understanding of the figure, refer to
the colour section (Figure 11).
in stiffness in a particular direction can be achieved by orienting the
fibres (Figure 9.2a). However, when fibres are oriented, the increase in
mechanical properties is only seen in the direction of the fibres - the
composite is stronger in the direction of the fibres than if load is applied
perpendicular to the fibre direction.
Bioactive composites containing bioactive glass within a biodegradable
polymer matrix can be produced in highly porous three-dimensional (3D)
structures, which are often known as tissue scaffolds because they can act
as temporary templates to guide tissue growth and repair [2, 3]. Porosity
of
m are desirable as well as high pore
interconnectivity in order to facilitate the attachment and proliferation
of cells and the ingrowth of new tissues into the network, as well as
to enable mass transport of oxygen, nutrition and waste products. In
general, scaffold porosity, pore morphology and pore orientation must
be tailored for the particular tissue under consideration, and there is
great influence of scaffold porosity and pore structure on successful bone
repair.
This chapter is devoted to bioactive-glass-containing composite scaf-
folds for healing bone defects. We first describe the biodegradable
polymers that are candidates to be combined with bioactive glasses to
form porous composites for tissue engineering. Subsequently, the chapter
discusses the rationale for the development of composite materials incor-
porating bioactive glass, describing also the technologies employed to
fabricate composite scaffolds. Specific examples for bone repair are pre-
sented. The goal of this chapter is thus to allow readers to appreciate
the prominent role of bioactive glasses in bioactive composite materials
and to fully understand the main principles behind the development of
bioactive-glass-containing composite scaffolds for bone repair.
∼
90% and pores of size
>
200
μ
