3D Printed Templating of Extrinsic Freeze-Casting for Macro-Microporous Biomaterials.

As with most biological materials, natural bone has hierarchical structure. The microstructural features of compact bone are of various length scales with its porosity consisting of larger osteons (∼100 μm diameter) and vascular channels, as well as smaller lacuna spaces (∼10 μm diameter). In this study, the freeze-casting process, which has been previously used to form biocompatible porous scaffolds (made with hydroxyapatite, HA) has been improved to mimic the intrinsic hierarchical structure of natural bone by implementing an extrinsic 3D printed template.