Chitosan-based scaffolds deliver growth factors in a
controlled fashion to promote the in-growth and biosynthetic
ability of chondrocytes. Lee et al. [244] reported
porous collagen/chitosan/GAG scaffolds loaded with transforming
growth factor (TGF)-1. This scaffold exhibited
controlled release of TGF-1 and promoted cartilage regeneration.
The addition of chitosan to the collagen scaffold
improved the mechanical properties [244] and the stability
of the collagen network by inhibiting the action of collagenases
[245]. Kim et al. used a porous freeze-dried chitosan
scaffold incorporating TGF-1-containing microspheres,
for the treatment of cartilage defects [246]. The TGF-1 was
released in a sustained fashion, and promoted chondrocyte
proliferation and matrix formation. In a similar trial, Lu
et al. studied the effect of intraarticular injection of chitosan
on regeneration of articular cartilage. An increase in epiphysis
cartilage in the tibial and femoral joints was seen with
an activation of chondrocytes proliferation. Similarly, an
intra-articular fibrous tissue was observed for the 6 weeks
of the experiment, together with residual injected chitosan
[247].
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