Our bones are a matrix of minerals and other substances, including living cells, though most people don't think of them that way and assume bones are 'natural' — but nature can be coaxed to do all kinds of things.
MIT engineers have coaxed bacterial cells to produce biofilms that can incorporate nonliving materials, such as gold nanoparticles and quantum dots. These "living materials" combine the advantages of live cells, which respond to their environment, produce complex biological molecules, and span multiple length scales, with the benefits of nonliving materials, but they add functions we don't usually associate with biology.
Self-assembling materials