Articular cartilage has limited potential for repair. There have been
various attempts aimed at improving the repair process in articular
cartilage. Transforming growth factor-ß1 (TGF-ß1)
has a stimulatory effect on chondrogenesis in periosteal explants.
The purpose of the present study was to determine the effect of
brief exposures (i.e., thirty and sixty minutes) of high concentrations
of TGF-ß1 on periosteal chondrogenesis.
Five hundred and seventy-three periosteal explants were harvested
from forty-six two-month-old male New Zealand White rabbits. Explants
were exposed to 50 or 100 ng/mL of TGF-ß1 for thirty or
sixty minutes. The amount of cartilage formed was then determined
with use of a standardized six-week agarose culture assay.
There was a significant increase in the amount of cartilage formation
(p < 0.01), Type-II collagen content (p < 0.05), and sulfate
incorporation (p < 0.0001) in explants treated with TGF-ß1.
Maximal stimulation occurred following exposure to 100 ng/mL of
TGF-ß1 for thirty minutes. There was also an increase in
chondrocyte proliferation as measured by [
H-] thymidine incorporation on day 5 of culture (p < 0.049).
Conclusions: The findings of this study indicate that exposure to
TGF-ß1 has a stimulatory effect on periosteal chondrogenesis.
This stimulatory effect is observed even with a very brief exposure
time of thirty minutes.
A possible clinical application of these findings is exposure of
periosteal grafts that are currently utilized clinically to resurface
articular defects to TGF-ß1 during the short time between
graft procurement and implantation into the joint. This may obviate
the need for intra-articular administration of TGF-ß1 and
may enhance the ultimate graft incorporation and quality of cartilage