Figure 1.

Role of hyaluronan in increasing tissue interstitial pressure. Hyaluronan forms long chains creating a highly osmotic environment that produces edema and increased interstitial pressure. Despite the fact that the diagram only shows a tetrasacharide, hyaluronan is a very lengthy unbranched chain of repeating disaccharides. Red arrows indicate the hydrophilic parts of glucuronic acid and N-acetyl glucosamine, proving the highly hydrophilic ability of hyaluronan. Increased hyaluronan in tumors is an early event occurring in TME, which leads to increased interstitial pressure due to its hygroscopic properties, causing an obstacle to the adequate delivery of chemotherapeutic drugs.