Hyaluronic acid
Hyaluronic acid (HA) or hyaluronan is a natural glycosaminoglycan copolymer of D-glucuronic acid and N-acetyl-D-glucosamine. Hyaluronic acid can be found in articular cartilage and the synovial fluid. It is degraded by cell-secreted hyaluronidase. Its molecular weight varies and can go up to 1-2 million Da.
Hyaluronan can be prepared from a variety of animal tissues therefore it possesses a risk of animal-derived pathogens.
Figure 1: Structure of hyaluronic acid.
Hyaluronic acid (HA) has been used successfully as hydrogels but it is difficult to tailor the mechanical properties of this natural scaffold according to tissue requirements.