Engineering Graded Tissue Interfaces - Structural Interfaces and Attachments in Biology - page 303

Fig. 14.4 Continuously
graded designs attempt to
make higher resolution in
physical and chemical
properties (adapted, with
permission, from [ 108 ])
Continuous gradient-based bioactive signal delivery systems have recently been
applied in the area of interfacial tissue regeneration. Various strategies have been
developed to create gradients of bioactive signals. Studies have shown that within a
tissue and at the interface the biological activity is maintained by the coordinated
activity of multiple signals. At the interface, the presence of biological signals in the
adjacent neighboring tissue enhances the stability of the other.
Wang et al. [ 44 ] looked into the influence of a continuous linear or reverse gradient
of IGF-1 and BMP-2 for osteochondral regeneration. The growth factors were
encapsulated in PLGA or silk microspheres and suspended in alginate/silk solution.
A continuous gradient of growth factors in alginate/silk scaffolds was fabricated.
Representative sections of the scaffold along the linear gradient were analyzed for
osteogenic and chondrogenic markers. The results of the study indicated that hMSCs