A sub-field of materials science dealing with things that can be safely implanted in the human body, molecules found in living things or molecules similar to those found in living things and the complex structures that they form, artificially grown tissue, and biomimetic and natural materials.

Natural or synthetic materials that can be safely implanted in the human body for medical purposes. Titanium and cobalt-chrome alloys for artificial hip implants, fake bone coatings that go on the surface of hip and knee implants, and the smooth ultra high molecular weight polyethylene that is used as a sort of lubricant or running surface between the two halves of the joint.

Biomolecules such as drug delivery vectors can also be considered biomaterials. Lipid and protein packages as well as small ceramic objects are being tested for the controlled release of drugs within the body.

The materials used to make dissolvable or biodegradable stitches are among the first biomaterials used as scaffolds for tissue engineering.

Wood, silk, and cotton are all extremely important natural materials. Biomimetic materials are synthetic materials that are specially designed to imitate some of the better features of materials made by living things. In theory, spider silk could be used to make bullet proof vests far superior to those that are made from synthetic materials like Zylon, Kevlar, and Spectra. Some silkworms have been genetically engineered to produce silk that is far stronger than run of the mill silk.

Problems with Artificial Hips

Total hip replacement has become common among the elderly. The material, Ultra High Molecular Weight Polyethylene, is used as a lubricant between the "ball" and "socket" of the artificial hip joint. Over time, some of this plastic wears down and makes its way into the muscle tissue surrounding the joint. This inflames the immune system and sometimes results in pain, swelling, and even worse, the loosening of the "socket" portion of the artificial hip. One of the solutions of this problem has been to sinter metal beads onto the outer surface of the "socket" so that it does not loosen up as easily.