Biomedical Engineering Reference
In-Depth Information
unexpected change of soft tissue overlying the graft, and a potential
for late exposure. So attention was paid to biodegradable scaffolds.
Oneofthemwassynthesizedbymaterialswithathree-dimensional
structure, which provided a good environment for bone regener-
ation and its surface facilitated cell attachment, proliferation, and
osteogenicdifferentiation.
9
The pore average was 200 to 400
μ
m in diameter, the
μ
interconnection average was 60
m, and the average void volume
was 90%. These ceramic composites were disk shaped, 5 mm in
diameter, and 4 mm in thickness. Following the concept of TERM,
we investigated the bone regeneration ability of the scaffolds:
β
-TCP alone and
β
-TCP loaded with MSCs. The results showed by
scanning electron microscopy (SEM) that a high percentage of open
pores with a connection to each pore and the surface were covered
by culture cells with a collagenous-like extracellular matrix (ECM)
(Fig. 40.2). The result of bone formation ability showed that some
maturebonetogetherwithcuboidalactiveosteoblastswasobserved
when alkaline phosphatase activity achieved a peak at two weeks.
10
And it confirmed that the bone areas increased in a time-dependent
fashion at one, two, four, and eight weeks after implantation. How-
ever, empty
β
-TCP blocks alone did not show any bone formation in
theporeareaattheirweeks,andonlyfibroustissueswereobserved
(Fig. 40.3).
10
On the other hand,
β
-TCP loaded with MSCs has excel-
lent osteogenic characteristics and supports its potential in tissue
engineering to repair bone defects. However, it is di
cult for new
bone to invade the defect for the lack of completely interconnected
pores, slow resorption of the ceramic, and lack of osteoinductive
properties, and in addition these delivery substances do not
have good plasticity and the cellular implantation procedure was
complicatedbyproblemsassociatedwiththedeliveryvehicles.Opti-
mally, these should combine with an appropriate rate of biodegrad-
ability with the capacity for the respective cells to multiply. But it
is di
cult to apply the block matrix for the field with the compli-
cated form in oral maxillofacial surgery and orthopedic surgery;
therefore next we paid attention to the injectable scaffolds with
plasticity.
Search WWH ::
Custom Search