Biomedical Engineering Reference
In-Depth Information
A
B
C
D
I
100
80
60
E
G
H
F
40
20
0
L
K
J
control
28
56
84
PCL-
Bone
Scaffolds
Connective tissue
OB
Bo
Bo
Bo
M
N
M
BV
OC
PCL
OC
PCL-
1
O
P
Q
R
CY
OB
FIGURE 2.7
Constructs with BMSC sheet scaffolds (mPCL-TCP) were implanted into nude rat harvested
after 28, 56, and 84 days. (A) Gross appearance of BMSC sheet scaffolds constructs with osteogenic induction
(
right
) and noninduction (control) (
left
) after 4 weeks. (B) X-ray detected bone-like tissue formation in 28 days.
(C) 56-day and (D) 84-day implants. (E) X-ray image of constructs without cell seeding (control). (F) Micro-
CT demonstrated the overall highly mineralized tissue similar to cortical (golden) and cancellous (red) bone in
implanted constructs after 28 days. (G) Micro-CT images disclosed the hard tissue formation within constructs.
Mineralized tissue with similar density with cancellous bone was detected (darker areas) while the lighter color
represented cortical bone. (H) Fluorescence was detected on the formed bone tissue after 28 days; the fl uores-
cence came from the cFDA labeled BMSC. (I) Micro-CT quantifi cation of implant tissue compositions depicted
substantial bone formation in the induction group, accounting for 40% total volume for the 28, 56, and 84-day
implantation, while the control group formed only connective tissue. (J) H&E staining shows lamellar bone-
like tissue formed in both outer part and interior of constructs after 28 days. (K) High-magnifi cation image
shows well organized lamellar bone-like tissue (Bo) with distinct osteocytes located within bone tissue. (L) The
typical osteoblasts (OB, black arrow) located on the surface of neomineralized tissue with marrow cavities and
blood vessels in 56-day implants. (M) Safranin-O staining demonstrated that hypertrophic chondrocytes (white
arrow) were observed in 56-day implants in very low numbers. High magnifi cation shows the chondrocytes
(white arrow) with weak safranin-O staining surrounded by the osteocyte (black arrow). (N) OCN staining.
Strong signals (arrow head) were detected on neomineralized tissue while very weak to no signals were detected
on chondrocyte like cells (O). (P) Collagen type I staining. Extensive staining was detected on the neomineralized
tissue in constructs. (Q) Collagen type II staining. Limited signals (arrow head) were detected on chondrocyte-
like cells while no staining for the mineralized tissues (R). BV, blood vessel
+
red blood cells; Ma, marrow; OB,
osteoblast; Bo, bone; OC, osteocyte; CY, chondrocyte. Scale bar: (J) 200 µm; (H-Q) 50 µm. (Zhou, Y., Chen, F.,
Ho, S.T., Woodruff, M.A., Lim, T.M., Hutmacher, D.W.
Biomaterials
. 28, 814-824, 2007. With permission from
Wiley and Elsevier.)
fi bers with controllable hollow cavity diameter and shell thickness. They utilized viscous encapsula-
tion to produce fi bers with shell-core confi guration via extrusion. The inner core polymer was then
removed by selective dissolution. The extrudates were then organized into 3-D matrices, which can
be customized into various shapes using RP.
