CUSTOMIZED NANOCOMPOSITE SCAFFOLDS FABRICATED VIA SELECTIVE LASER SINTERING FOR BONE TISSUE ENGINEERING - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 942

Figure 45.9. (a) BSA-loaded Ca-P/PHBV nanocomposite scaffold pro-
duced via SLS, (b) morphology of one layer of sintered scaffolds, and
(c) close view of the strut surface.
The BSA-loaded Ca-P/PHBV microspheres were subsequently
subjected to SLS for scaffold fabrication. The bar-shaped tetragonal
porous scaffold model, as shown in Fig. 45.6a, was used in scaffold
production. During the sintering process, the part bed temperature
wasfixedat35 ◦ C,thescanspeedat1,257mm/s,andtherollerspeed
at 127 mm/s. The layer thickness was kept constant at 0.15 mm for
all scaffolds according to the optimization results obtained in our
previous SLS experiments. The laser power and scan spacing were
set at 12.5 W and 0.10 mm/s, respectively. Fig. 45.9a shows BSA-
loaded Ca-P/PHBV nanocomposite scaffolds produced via SLS. The
typical layer morphology of BSA-loaded Ca-P/PHBV nanocomposite
scaffold is presented as Fig. 45.9b. Once again, the SEM images indi-
cated that the morphology of each layer of sintered scaffolds was
well preserved and that the pores were clearly identified and com-
parable to the designed scaffold model. A close observation of the
strut surface, as shown in Fig. 45.9c, revealed necking among adja-
cent microspheres. The loaded BSA in fused microspheres may lose
some bioactivity because the microspheres were subjected to high
thermalenergyduringsintering.TheactualBSAloadinglevelandEE
for sintered Ca-P/PHBV scaffolds, as were calculated on the basis of
the amount of initially applied BSA during microsphere fabrication,
were 2.96 ± 0.15 μ g/mg and 13.63 ± 0.71%, respectively. The low EE
value was due not only to the denaturation of BSA during the laser
sinteringprocessbutalsotothelowEEofCa-P/PHBVnanocompos-
ite microspheres fabricated. Experimental results showed that after