Currently, the paramount problem in the field of
biomaterials, the science of replacing diseased tissue with
human-made implants, is control over the interface, or
surface, between implanted biomaterials and living
tissues. The physical properties of most tissues can be
matched by careful selection of raw materials: metals,
ceramics, or several varieties of polymer materials. Even
the requirement that biomaterials processed from these
materials be nontoxic to host tissue can be met by
techniques derived from studying the reactions of tissue
cultures to biomaterials or from short-term implants. But
achieving necessary matches in physical properties across
interfaces between living and non-living matter requires
knowledge of which molecules control the bonding of
cells to each other—an area that we have not yet explored
thoroughly. Although recent research has allowed us to
stabilize the tissue-biomaterial interface by controlling
either the chemical reactions or the microstructure of the
biomaterials, our fundamental understanding of how
implant devices adhere to tissues remains woefully
incomplete.