Figure 3.

Schematics of different fabrication methods that can be used for bone-to-soft interfaces, from highly organized interfaces (left) to randomly organized interfaces (right). (a) Digital light processing-based 3D/bioprinting showing that sequential input of different digital masks can be used to generate patterns with interfaces of different materials. Panel a is reproduced with permission from ref (186). Copyright 2021 National Academy of Sciences. (b) Extrusion-based 3D/bioprinting showing that the combination of multiheads containing different bioinks can be used to generate scaffolds with gradients (in this example, cell gradients mimicking articular cartilage cell density. Panel b is reproduced with permission from ref (187). Copyright 2021 MDPI. (c) Electrospinning setup with two spinnerets creating a transitory region. Reproduced with permission from ref (212). Copyright 2021 John Wiley and Sons. (d) Iterative freeze-casting (or ice-templating) can be combined with freeze-drying to achieve bilayered structures with a defined interface.