Biomedical Engineering Reference
In-Depth Information
composites exhibit high bioactivity, assessed by the formation of HCA
on the composite surfaces upon immersion in simulated body fluid
(SBF) [3].
Owing to the potential advantages the system offers, PDLLA-Bioglass
composites have been investigated in terms of their
in vitro
and
in vivo
response, as summarised elsewhere [3]. It has been shown that PDLLA-
Bioglass foams support the migration, adhesion, spreading and viability
of bone cells. In addition, the adhesion, growth and differentiation
of human bone marrow mesenchymal stem cells (MSCs) on compos-
ites made of PDLLA foams and Bioglass particles was investigated
in
vitro
and
in vivo
and the potential for
in vivo
bone formation on the
composites was analysed in immuno-compromised animals. Moreover,
PDLLA-Bioglass films were shown to enhance bone nodule forma-
tion and displayed enhanced alkaline phosphatase activity of primary
human foetal osteoblasts in the absence of osteogenic supplements. The
attachment and spreading of osteoblast cells onto PDLLA-Bioglass 3D
composite foams has also been investigated. The results achieved so far
have demonstrated that the regulatory role on cell differentiation and
mineralisation of the Bioglass-containing PDLLA composites is likely
to be a combination of both the cell-scaffold interaction (including
topographic contributions) and the ionic release of Bioglass dissolution
products discussed above. It is hoped that such composites can be used
to stimulate repair of intervertebral discs [12].
9.6 FINAL REMARKS
The topics covered in the present chapter are intended to demonstrate
how bioactive glass has a major application in the development of scaf-
folds for bone regeneration. This is a very active research field worldwide
with bioactive glass (e.g. 45S5 Bioglass) having great biological benefits
for promoting bone growth, but being brittle when used alone. Combi-
nation with biopolymers in tailored composite scaffolds can extend their
application to tough load-bearing constructs. This R&D sector involves
efforts from a wide range of disciplines, including cell biology, materials
science, biochemistry, pharmaceutical sciences and clinical medicine.
From the materials science perspective, the challenges ahead include
the design and reproducible fabrication of bioactive and bioresorbable
3D scaffolds, which are able to maintain their structural integrity for
predictable times, even under load-bearing conditions.
