Engineering Graded Tissue Interfaces - Structural Interfaces and Attachments in Biology - page 306

abrupt distinct layers and enable a smooth transition of properties, and may be better
suited for addressing the regeneration of interfaces between tissues with drastically
different mechanical behaviors. Electrospinning is a good technique to engineer
graded structures that mimic the native ECM, but the ability to recreate the mechan-
ical properties of the tissue with electrospinning may be questionable. Recent
approaches to incorporate bioactive molecules and osteoconductive materials and
methods to make layer by layer scaffolds show a promising trend. Advanced
fabrication designs using CAD enable the fabrication of gradient structures similar
to tissue interfaces. Therefore, use of biomimetic scaffolds with transitions in
physico-chemical and biological signals similar to native tissue interfaces may
significantly improve our efforts for in vitro and in vivo engineering of interfaces.
Native (uninjured) tissue interfaces show transitions in cell type, structure,
composition, organization of ECM, chemical signals, mineralization, mechanical
properties, and biological function. An ideal scaffold should be able to accommo-
date all of these transitions to transmit the properties of one tissue to another.
However, it is rather complex to incorporate all of these transitions in the engineer-
ing of graded scaffolds for interfaces. It should be remembered that the scaffolds are
only temporary structures that signal the host cells to infiltrate and synthesize the
native tissue. Therefore, the importance is not in the complexity of the architecture
or the physico-chemical properties of the 3D scaffolds, but rather in the ability of
this temporary matrix to direct cells to form an interface similar to native tissue.
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