Biomedical Engineering Reference
In-Depth Information
Table25.2. Scaffoldsmanufacturedusing3DPandusedforbone
tissue engineering purposes.
Scaffold material
Properties
References
HA
Osteoconductive, highmechanical strength,
5, 48, 49, 56-58
minimal inflammatory response
PLGA
Biodegradable, osteoconductive, minimal
5
inflammatory response
PLA
Biodegradable
50, 54, 59
(Table 25.2). 46 - 52 Porous HA scaffolds have been created using 3DP
withaminimumporesizeof450
μ
mandaminimumwallthickness
m. 49 Though these results were promising a possible draw-
back of 3DP is highlighted, as the size of the pores achieved were
not as small as the optimal pore size for bone tissue engineering,
which is approximately 300 μ m. 53 Just as indirect approaches were
utilized with SLA, bone tissue engineering scaffolds have been man-
ufactured using an indirect 3DP approach. In this approach molds
were created using 3DP, and PLGA scaffolds was cast around them.
Porogen leaching was then used to achieve small pore sizes. 47 This
work showed that 3DP could be an effective tool for scaffold design
but that other techniques may be necessary to achieve the porosity
desired. Other problems associated with 3DP include limited scaf-
fold material choice, required processing of many scaffold materials
before use in 3DP,and possibleshrinking of scaffoldduring curing.
μ
of 330
25.3.2 Biological Implications
A significant drawback to the use of 3DP for fabrication of bone
tissue engineering scaffolds is the inability of this process to be
used to fabricate scaffolds with small pore sizes. The indirect
3DP approach overcomes this limitation as it allows for a con-
trolledmacroarchitecture, whichcanbecustommadetofitadefect,
while the necessary microarchitecture can be attained through the
use of a secondary method such as porogen leaching or emul-
sion. These indirect 3DP scaffolds have a significant advantage
over scaffolds made through traditional manufacturing techniques
as they have increased mechanical properties, controlled global
 
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