Biomedical Engineering Reference
In-Depth Information
resolutions as small as 20
μ
m. SLA was first used to aid in the
treatment of bone injuries by oral and maxillofacial surgeons to
create a model of complex cranial injuries.
17
,
22
Surgeons utilized
computed tomography (CT) to develop 3D displays of the injury
site and then fabricated a detailed model to aid in surgical plan-
ning. Tissue engineers have now adapted this idea to use SFF to
create polymer scaffolds based on CT images of an injury site in
order to create a platform for bone tissue engineering that will fit
precisely in a defect. Several groups have evaluated the effective-
ness of scaffolds developed through SLA for cell-based tissue engi-
neering (Table 25.1). Research has shown that SLA can be used
to make PPF scaffolds with controlled architectures.
3
,
4
,
23
-
27
Com-
monly used in bone tissue engineering applications, PPF has strong
mechanical properties, as well as being biodegradable.
23
,
28
-
33
The
ability of SLA to be used in the manufacture of PPF scaffolds pro-
videsgreatutilityfortheprocessinbonetissueengineering,though
research has shown that further biological evaluations must be
completed in order to optimize the manufacturing process of the
scaffolds.
4
SimilarinprincipletoSLA,micro-SLAhasbeendevelopedtocre-
ate scaffolds with even smaller architectures by focusing the laser
beam more precisely. This technique allows for resolutions in the
500 nm range, and it has been demonstrated that highly structured
PPF scaffolds could be developed using this technique and that the
scaffolds would support the growth of pre-osteoblasts.
24
,
25
Despite
these promising developments, SLA has several drawbacks to its
effective use in bone tissue engineering. Many common biomateri-
als used in bone tissue engineering cannot be used in SLA as high
Table 25.1. Scaffolds manufactured using SLA and used for bone
tissue engineering purposes.
Scaffold material
Properties
References
PPF
Biodegradable, biocompatible, smallpore size
3, 4, 24, 25
PEOand PEGDA
Low mechanical properties, not biodegradable,
37
cell incorporation
HA
Indirect scaffold formation, osteoconductive
34-36
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