Biomedical Engineering Reference
In-Depth Information
17.5 SEM images of cross-linked PLA porous scaffolds: Lait-X/b and
Lait-X/c, for 350
magnifications. Reprinted with permission
from Wiley-VCH (Sakai et al., 2012).
6
and 750
6
confirming biocompatibility through the cell-scaffold interaction. The in-
vitro degradation of the PLA thermoset scaffolds in a phosphate-buffered
solution was faster for samples prepared by foaming and subsequent
leaching (Sakai et al., 2012). The agglomeration of the smaller crystal (solid
porogen) within the 3D polymer matrix enables the creation of an
interconnected pore network with well-defined pore sizes and shapes.
17.4.2 Thermally-induced phase separation (TIPS)
Three-dimensional
(3D) resorbable polymer scaffolds with very high
porosities (
97%) can be produced using the TIPS technique to give
controlled microstructures that form scaffolds for tissues such as nerve,
muscle, tendon, intestine, bone and teeth (Boccaccini and Maquet, 2003).
The obtained scaffolds are highly porous with an anisotropic tubular
morphology and extensive pore interconnectivity. The microporosity of
TIPS-produced foams, their pore morphology, mechanical properties,
bioactivity and degradation rates can be controlled by varying the polymer
concentration in solution, the volume fraction of the secondary phase,
quenching temperature and the polymer and solvent used (Boccaccini and
Maquet, 2003).
When dioxane alone was used, the porous structure resulted from a solid-
liquid phase separation of the polymer solution. During quenching, the
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