Mucins are already used as hydrating components in several cosmetic products. And recent studies have shown that they can be used as antiviral and antibacterial agents, and could soon find other applications in the food and cosmetic industries. But the development of technological applications of mucins is delayed by the lack of control over the quality of the mucin molecules that are used. As with other polymers of biological origin, the source and extraction protocols that are used can lead to variability in the product.
We are establishing a series of assays that once put together will provide a quality control benchmark for mucins. A series of five parameters are explored for their consistency and representativeness of the quality of mucins.
Our mucus layer is an ever-changing material. Its chemical composition, polymer concentration and ionic strength change in response to physiological signals and impact its rheology, barrier properties, and lubricity. For instance, fluctuating hormone concentrations changes the viscosity of cervical mucus to facilitate sperm movement during ovulation. Mucus gels are also altered in conditions such as preterm birth, inflammatory bowel disease, and dry mouth/eye, where the layer is either impoverished in mucus, or the mucin molecules are altered in their physico-chemical properties.
Unfortunately there are very few strategies to recover a healthy mucus layer in these difficult cases. We are developing ways to engineer the mucus layer by topical treatments. We particularly focus on restoring the native protective abilities of our mucus layer (hydration, lubrication, barrier) when it is altered.
Mucins possess a range of functionalities that could find valuable technological applications. Their high hydration, lubrication, and barrier properties have the could be key to solving challenges in the food and biomedical industries.
Thin nanometer-thick films of mucins can also be assembled using lectins (carbohydrate binding proteins) as crosslinker. The films have been used as on-demand release system for cell backpacks developed by the Rubner group at MIT.
We showed that mucins can be assembled in covalently crosslinked hydrogels that can bind to model hydrophobic and hydrophilic drugs. Both drugs were release in a sustained manner thanks to the sticky nature of mucins.
Mucins could help solve on-going challenges in the delivery of biologics. For instance, the epidermal growth factor (EGF) is naturally found in association with mucins in saliva and in the gut and is responsible for the healing effect of wound licking by animals. However nothing is known about potential mucin-EGF interactions or synergistic effects. Better knowledge of mucin/EGF interactions could lead to new, more effective material to deliver EGF from wound dressing materials. Indeed, mucins possess inherent properties that make them well suited for this application. This includes high hydration, the ability to form protective dressings to close-off wounds, and potentially, the capacity to bind and deliver bioactive molecules that promote epithelialization, such as EGF.