Bioactive Glass-Based Scaffolds for Bone Tissue Engineering - Tissue Engineering: Cell-Surface Interactions for Tissue Culture - page 204

Fig. 4 Scanning electron microscopy (SEM) image of the surface of a 45S5 Bioglass -derived
scaffold fabricated by the foam replication method similar to that reported in Ref. [ 72 ]
the foam replica method, other techniques have been considered for fabricating
porous glass-ceramic scaffolds. For example, organic particles such as starch, rice,
potato, or corn grains [ 15 ] swell in water and leave a porous and highly inter-
connected structure following burn-out from the glass slurry. Porosity can also be
introduced by addition of thermally removable phases such as polyethylene par-
ticles [ 102 ]. Sugar or salt leaching [ 29 , 44 ] is another common method of pro-
ducing porous scaffolds. Particles are incorporated into the slurry and leached out
upon sintering, leaving an interconnected pore network. The compaction and
sintering of melt-spun fibers from bioactive glass is another method of producing
scaffolds [ 31 , 90 , 99 ]. After glass production, fibers can be manufactured by melt
spinning and packed in a ceramic mould and sintered. It is also possible to
manually form melt-spun fibers [ 105 ]. Freeze casting techniques uses camphene,
ice or water and glycerol as freeze vehicles [ 112 ]. After mixing the glass powder
with the relevant vehicles, the slurries are cast and frozen at temperatures between
-20 and -70 C, followed by a sintering process.
4.2 Mechanical Properties
In a recent study, Fu et al. [ 94 ] fabricated bioactive glass (13-93) scaffolds with
oriented (i.e., columnar and lamellar) microstructures and found that at an
equivalent porosity of 55-60%, the columnar scaffolds had a compressive strength