One of Karl Meyer’s most notable achievements was the isolation and characterization of hyaluronan (also known as hyaluronic acid). Hyaluronan is a unique glycosaminoglycan due to its simple structure and remarkable properties. It is abundant in connective tissues and is essential for tissue hydration, lubrication, and cellular processes such as migration and proliferation. Meyer's work paved the way for its extensive application in medical and cosmetic fields.