Figure 2.

Schematic diagram of osteochondral tissue-engineered (OCTE) strategies used for the biofabrication of OC tissue replicates in vitro. Different approaches can be classified according to the number of layers and gradient properties of the designs: monophasic scaffolds are formed by a single homogeneous layer, while discrete gradient constructs can be bi- (two layers) or multiphasic (three or more layers). In the latter, each layer represents a specific region of the OC unit. Because multiphasic, discrete, scaffolds are associated with abrupt transitions between different phases, continuous gradient scaffolds have also been developed, in which a gradual transition between separate regions better emulates the native features of the joint. Adapted from [81] with permission from Elsevier. Copyright © 2016, Acta Materialia Inc. Published by Elsevier Ltd.