The mechanism of degradation for these types of polymers includes hydrolytic instability, hydration, molecular backbone cleavage, loss of molecular weight, and solubilization. Typical applications of these polymers include their use in absorbable sutures. These sutures degrade slowly into byproducts that the body can remove itself through natural functions such as phagocytosis, thus affording time for the wounded tissue to complete its own healing process. The sutures eliminate the need for a second operation to remove them. Biodegradable polymers show promise in many tissue engineering applications due to their ability to degrade while encouraging functional tissue from the body to take its place.
Biodegradable polymers can be natural or synthetic.
This category consists of inorganic, nonmetallic compounds that exhibit a variety of combinations of ionic and covalent bonding. They have been widely used in biomedical applications for load bearing implants and the dental industry. Most members of this group are characterized by a high Young's modulus, very low elasticity, and a hard, brittle surface. They can be used for load bearing applications, such as total hip replacements. Alumina, for example, is often used as a pair in a ball and socket hip implant.