Biodegradation refers to the continuous discharge of materials from the body in the process of tissue growth through dissolution, enzymatic hydrolysis and cell phagocytosis. The repaired tissue completely replaces the position of implanted materials, and the materials do not have residual properties in the body.

Biodegradable plastics are a kind of plastics synthesized from natural polymers or materials modified from natural polymers. Unlike biodegradable plastics, fully biodegradable plastics do not contain biodegradable components, so they can be completely decomposed by microorganisms without residues.