Mucus network

The mucus network is a complex, three-dimensional hydrogel that lines the epithelial surfaces of the respiratory, gastrointestinal, and urogenital tracts. It is primarily composed of large, heavily glycosylated proteins known as mucins, such as MUC5AC and MUC5B in the airways and MUC2 in the intestines, which cross-link via disulfide bonds to form a protective mesh [1.1.4, 1.3.1]. This network serves as a critical biological barrier, providing lubrication, maintaining surface hydration, and selectively filtering pathogens and toxins while allowing the exchange of nutrients and gases [1.3.2, 1.3.5]. In pathological conditions like cystic fibrosis, COPD, and asthma, the network becomes hyper-viscous and stagnant due to mucin overproduction, dehydration, or the accumulation of extracellular DNA from inflammatory cells [1.1.2, 1.2.5]. Therapeutic interventions target the physical properties of this network to restore clearance, using mucolytics to break chemical cross-links, DNases to degrade structural DNA, or osmotic agents to increase hydration [1.2.5, 1.4.1]. Understanding the rheological and biochemical properties of the mucus network is essential for developing effective transmucosal drug delivery systems and treating chronic obstructive airway diseases [1.3.3, 1.4.2].

Other names

Mucin networkMucus barrierMucus gelAirway mucusIntestinal mucus barrierMucosal barrier

Disruption of disulfide bonds in mucin polymers, hydrolysis of extracellular DNA, osmotic hydration of the mucus gel, and stimulation of mucociliary clearance.