Tracheal stents can be lifesavers for people who have trouble breathing because of a constriction due to a tumor, congenital defect, or some other reason. These types of stents have been known to slip out of place as well as help develop pneumonia because they typically lack any anti-bacterial properties.
Researchers from the Fraunhofer Institute for Interfacial Engineering and Biotechnology in Stuttgart and University Hospital of Würzburg are working on stent coatings that will both help in securing the stents in place as well as help goblet and cilia cells settle on the stent to prevent the spread of infections.
The scientists used stents lined with a polyurethane (PU) film, which were produced by Aachen-based Leufen Medical GmbH. In the ensuing tests, a wide variety of different coatings were applied to the PU film: In addition to synthetic polymers composed of organic acids, the researchers also tried out biological proteins such as fibronectin and type-I collagen. The coating was modified again using plasma technology, with vacuum-ionized gas being used to treat the surface. The experts used an untreated PU film for control purposes. “In order to find out which of the surface coatings was the most suitable, we brought both lab-cultivated cell lines and human primary tracheal epithelial cells into contact with the films in cell culture vessels. What we wanted, of course, was for the primary respiratory cells from human tissue to attach themselves to the film,” explains Hampel [Dr. Martina Hampel, scientist at Fraunhofer Institute for Interfacial Engineering and Biotechnology]. The researchers achieved their best results with the protein-coated film, on which the primary tracheal epithelial cells grew particularly well and multiplied. “The respiratory cells proved to be more vital on bioactive films rather than on ones treated with plasma. By contrast, polymer-coated film turned out to be completely useless,” says Hampel.
The laboratory tests have since been completed, and animal tests are in preparation. If the good lab results are confirmed in these tests, the next step will be to conduct clinical trials of the modified stents at the Schillerhöhe specialist lung clinic, part of the Robert Bosch Hospital.
Full story: Non-slip tracheal implants…