Morphological and Mechanical Biomimetic Bone Structures

ACS Biomater Sci Eng. 2017 Nov 13;3(11):2761-2767. doi: 10.1021/acsbiomaterials.6b00652. Epub 2017 Jan 9.

Abstract

Cortical bone is an example of a mineralized tissue containing a compositional distribution of hard and soft phases in 3-dimensional space for mechanical function. X-ray computed tomography (XCT) is able to describe this compositional and morphological complexity but methods to provide a physical output with comparable mechanical function is lacking. A workflow is presented here to establish a method of using high contrast XCT to establish a virtual model of cortical bone that is manufactured using a multiple material capable 3D printer. Resultant 3D printed structures were produced based on more and less remodelled bone designs exhibiting a range of secondary osteon density. Variation in resultant mechanical properties of the 3D printed composite structures for each bone design was achieved using a combination of material components and reasonable prediction of elastic modulus provided using a Hashin-Shtrikman approach. The ability to 3D print composite structures using high contrast XCT to distinguish between compositional phases in a biological structure promises improved anatomical models as well as next-generation mechano-mimetic implants.

Keywords: 3D printing; X-ray tomography; additive manufacturing; bone; composites; mechanics.