Biomedical Engineering Reference
In-Depth Information
Table 25.4. Scaffolds manufactured using FDM and used for
bone tissue engineering purposes.
Scaffold material
Properties
References
PCL, HA-PCL
Support osteoblast proliferation
7, 8, 73, 75-81
and phenotype, bioresorbable
PLA, PLLA
Biodegradable
75, 82
PP, PP-TCP
Not biodegradable, mechanically strong,
74
supportcellgrowth
osteocalcin expression as well as visualization of the extracellu-
lar matrix using SEM. Scaffolds for this tissue engineering strat-
egy require support of the growth, interaction, and extracellular
matrix production of both osteoblasts and chondrocytes. The scaf-
folds were constructed with a pore size from 300 to 568
μ
m, a
porosity of
60%, and a partition in the scaffold to separate the
bone and cartilage components. Results demonstrated the scaffolds
to be conducive for cell communication, growth, and attachment, as
shown by confocal microscopy and SEM to visualize cells. The scaf-
foldsbecamecompletelyfilledwithcellsandmatrix,whichcouldbe
attributed to the interconnected scaffold architecture and the large
available surface area. Higher ALP expression was observed in the
osteochondral scaffold seeding with chondrocytes and osteoblasts
than the control, indicating the controlled architecture scaffolds
developed using FDM could potentially be used for osteochondral
tissue engineering. Another important aspect to mediating the bio-
logical interaction between the cells and the scaffold is the ability
of the scaffold to be incorporated with bioactive factors. In another
study utilizing PCL, scaffolds fabricated using FDM were shown to
be effective as a delivery system for recombinant human BMP-2
(rhBMP-2), a growth factor shown to enhance both osteoinduction
andosteoconduction.
79
,
80
TheloadedrhBMP-2wasshowntohavea
loadinge
ciencyashighas73%andtoremainbioactive.Thebioac-
tivity of the rhBMP-2 postrelease was verified by incubating human
osteoblasts for four days with the released rhBMP-2 and compar-
ing rhBMP-2 ALP levels to controls. The rhBMP-2 was shown to be
released from the scaffolds in both a burst and a pattern profile,
dependingontheloadingconcentration.Scaffoldswereseededwith
∼
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