An assembly configured for implantation in a living organism is provided. In some embodiments, the material includes a mechanical surface that has long range ordered micro-features. A repetitive pattern of hierarchical micro-features is incorporated in some embodiments, and in some embodiments the micro-features are composite in nature, and may include nano-structures. In one embodiment an assembly has a first article has a mechanical surface configured to be disposed in contact with a material that is not live biological tissue and a second article comprising a bio-interfacial surface configured to be disposed in contact with live biological tissue. Some embodiments include a screw or a post.
 This invention was made with government support under Contract No. DE-AC05-00OR22725 awarded by the U.S. Department of Energy. The government has certain rights in the invention.