The protein matrix and hard tissue of insects, worms, ants and spiders naturally contains metals such as zinc, manganese and copper. (nanotechweb.org)
Stage 4 — Extensive dental hard tissue loss and most of the tooth has lost its integrity. (consciouscat.net)
It means the researchers coated protein - like molecules on solid surfaces in a highly ordered way to create materials similar to hard tissue surfaces, like bones or sea shells. (pnnl.gov)