Which of these is NOT a natural polymer?

Poly(glycolic) acid is a synthetic polymer derived from glycolic acid, a small organic molecule. It is categorized as a biodegradable and bioabsorbable polymer commonly used in tissue engineering and sutures due to its favorable mechanical properties and degradation rates. Unlike natural polymers, which are derived directly from natural biological sources and typically exhibit complex structures and functions, synthetic polymers like poly(glycolic) acid are chemically engineered to achieve specific physical and chemical properties, making them versatile for various biomedical applications.

In contrast, cellulose, chitosan, and alginate are all examples of natural polymers originating from biological sources. Cellulose is a polysaccharide found in the cell walls of plants, providing structural support. Chitosan is derived from chitin, which is sourced from the exoskeletons of crustaceans and insects. Alginate is extracted from the cell walls of brown algae and is known for its ability to form hydrogels. These natural polymers are often utilized in tissue engineering due to their biocompatibility and biodegradability, mimicking the extracellular matrix that supports cells in biological systems.