Hydration of extracellular matrix

Hydration of extracellular matrix refers to the ability of the ECM's proteoglycans—especially those rich in glycosaminoglycans (GAGs) such as aggrecan, hyaluronan, and chondroitin sulfate—to retain water, regulating tissue compressibility, resilience, and molecular diffusion. The negatively charged GAGs attract sodium ions, which then draw in water by osmosis, maintaining tissue hydration and enabling biomechanical functions such as shock absorption in cartilage and proper signaling in other tissues. This hydrated state is crucial for tissue health; in pathology, loss or excess of ECM hydration can contribute to diseases such as fibrosis, osteoarthritis, and impaired wound healing. However, hydration itself is a property mediated by ECM components—most notably proteoglycans—and is not a standalone druggable target or molecular entity. Key point: “Hydration of extracellular matrix” is a critical property for tissue function but not a molecular receptor or protein, nor a canonical therapeutic target. It is mediated by molecules such as aggrecan, hyaluronan, and other proteoglycans.