Biomedical Engineering Reference
In-Depth Information
Figure 34.7.
Histology demonstrates that engineered cartilage heals ide-
ally with adjacent cartilage (
left
) and underlying cancellous bone (
right
).
Abbreviations
:NC,normalcartilage;RC,repairedcartilage;IF,interfaceheal-
ing; CB, cancellous bone. (Reprinted by permission from Ref. 8).
Moreover,theengineeredcartilageexhibitedenhancedECMpro-
duction and improved biomechanical properties, indicating that
engineered cartilage resembles the native articular cartilage not
only in morphology and histology but also in biochemical compo-
nentsand biomechanicalproperties.
15
Recently, induced bone marrow stem cells (BMSCs) with a chon-
drogenic phenotype were used to repair articular cartilage defects
in a similar model, except that the defects were created at non-
weight-bearing areas.
16
To prepare the scaffold, a silicone rubber
mold was created that contained a cylinder cavity with an 8 mm
diameter and a 6 mm depth. Thirty milligrams of unwoven PGA
fibers (Albany International Research, Albany, NY) were inserted
into the cavity and 0.3 mL of 1.5% polylactic acid (PLA) (Sigma,
St. Louis, MO) diluted in a dichloromethane solvent was added to
maintain the scaffold shape. The scaffolds were then removed from
the mold and sterilized by soaking in 75% alcohol and washed
three times with phosphate buffered saline (PBS), followed by two
washes with Dulbecco's Modified Eagle's Medium (DMEM). Chon-
drogenically induced or dexamethasone-treated BMSCs at passage
2(1.5
×
10
7
in 0.3 mL) were evenly dropped onto PGA/PLA scaf-
foldsrespectivelytoformcell-scaffoldconstructs,andtheconstructs
were cultured at 37
◦
C in a humidified atmosphere of 5% CO
2
for
four to five hours, which allowed complete adhesion of BMSCs to
the scaffold. Inductive and dexamethasone-containing media were
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