Bioinert Materials, Biologically inert, or  Bioinert materials are ones which do not initiate a response or interact when introduced to biological tissue. In other words, introducing the material to the body will not cause a reaction with the host. Examples of biomaterials include metals, ceramics, glass, and polymers. These biomaterials can be found in things such as contact lenses, pacemakers, heart valves, orthopedic devices, and much more. Biomaterials are non-viable materials that can be implanted to replace or repair missing tissue. They may be of natural origin or synthesized in a laboratory. When used in a medical application, biomaterials can be implanted to replace or repair missing tissue.