We are happy to announce a new publication in the ACS Biomacromolecules journal (doi: 10.1021/acs.biomac.7b01670, openly accessible through our publication list). The paper describes the reinforcement of the mucus barrier with short chitosan molecules. This work is a continuation of the mucus engineering work started late 2011 that led to a first publication in 2015 on the modification of mucin molecules to restore mucosal hydration and lubrication. In this new work, the goal was to find a way to modulate another important function of the mucus gel: its ability to act as a barrier against deleterious molecules and pathogens. The work is the result of a collaboration between our group at KTH (Stockholm, Sweden) and researchers at the Claude-Bernard University (Lyon, France) and Uppsala University (Uppsala, Sweden).
Reinforcing the barrier properties of mucus with chitosans.
This new publication describes the possibility of using chitosans to reinforce the barrier properties of mucus. Chitosans are natural molecules that are extracted from the shell of shrimps or the tissues of mushrooms. We show that if made small enough, chitosan molecules are able to diffuse into the mucus and strongly bind to the fibers that make up mucus.
The chitosan molecules then form bridges between the fibers, closing the pore of the mucus, and making it harder for molecules to penetrate. Chitosans are already widely used in the food and medical industries and are generally recognized as safe. We also saw no negative significant effect of the chitosans on the viability of epithelial cells cultured in vitro.
Modification of mucus by such a topical treatment could become a new way to address the breakdown of the mucus barrier in diseases such as inflammatory bowel disease or gastric ulcers. Of course, many challenges remain before this technology is ready to be translated clinically, including testing the approach on more complex mucus materials and tackling the challenge of delivery.
Following up with applications.
Our lab now continues to explore the potential of mucosal topical treatments to tune the properties of mucus. Chitosans are particularly interesting to use in that regard. For instance, Dr. Ulrike Schimpft has started to test the use of chitosans to prevent sperm cells from penetrating human cervical mucus. The project aim is to create the basis for a new generation of non-hormonal contraceptives for women in partnership with the Circle Biomedical company. More information regarding these exciting advances will come soon!