Biomedical Engineering Reference
In-Depth Information
Table 9.3
Fabrication routes for highly porous bioactive composites, their
advantages and disadvantages. (Reprinted with permission from [8]. Copyright
(2005) Expert Reviews Ltd.)
Fabrication route
Advantages
Disadvantages
Thermally induced
phase separation
(TIPS)
High porosities (
∼
95%)
Long time to sublime
solvent (48 hours)
Highly interconnected
pore structures
Shrinkage issues
Anisotropic and tubular
pores possible
Small-scale production
Control of structure and
pore size by varying
preparation conditions
Use of organic solvents
Compression
moulding/particulate
(porogen) leaching
Controlled porosity
Poor interconnectivity
especially at low
porosities
Graded porosity structures
possible
Difficult to generate
large structures
(over 3 mm thick)
No organic solvents
Not all particulates
leached
Solvent
casting/particulate
(porogen) leaching
Controlled porosity
Structures generally
isotropic
Controlled
interconnectivity (if
particulates are sintered)
Use of organic solvents
Microsphere sintering
Graded porosity structures
possible
Interconnectivity is an
issue
Controlled porosity
Use of organic solvents
Canbefabricatedinto
complex shapes
Solid freeform
fabrication (SFF)
Porous structure can be
tailored to host tissue
Resolution needs to be
improved to the
micro-scale
Protein and cell
encapsulation possible
Some methods use
organic solvents
Good interface with
medical imaging
be added. After the lactide's solvent is removed, the polylactide will
be a solid matrix. The salt particles can then be washed out with
water. However, little work has been done on producing bioactive
glass-polymer scaffolds using particulate (porogen) leaching. A problem
with this technique is achieving adequate pore interconnectivity at low
porogen (salt/sucrose) loadings, as many of the porogen particles may
