With their extraordinary adaptability and versatility, coatings made of polyurethane (PU) will soon be used to give such articles as catheters, leads and endoscopes particularly low-friction surfaces that are also resistant to mechanical and thermal stresses.

With their extraordinary adaptability and versatility, coatings made of polyurethane (PU) have conquered one area of application after another since their invention over 70 years ago. They are now poised for their next coup: They will soon be used to give such articles as catheters, leads and endoscopes particularly low-friction surfaces that are also resistant to mechanical and thermal stresses.

As Dr. Jürgen Köcher, an expert at Bayer MaterialScience, recently reported at the European Coatings Conference (ECC), Medical Coatings and Adhesives, in Berlin, the company is currently developing hydrophilic (having an affinity for water) PU coatings for medical devices. "The reduced friction makes devices coated with these materials particularly safe and easy to handle. For the patients, this means less pain," says Köcher.

There are two ways to manufacture the new coatings: one method uses waterborne PU dispersions, the other PU solutions. The waterborne coatings are particularly hydrophilic, whereas the solventborne coatings are further characterized by excellent mechanical stability (wet strength).

"Our objective is to offer the first commercial products for the coating of medical devices within the next few months," says Dr. Michael Mager, Head of the Medical Coatings and Adhesives unit of the Innovation and Business Creation division. Bayer MaterialScience is already providing samples of the new PU raw materials to select customers.

The new dispersions and solutions can be applied to medical devices or implants by means of spraying, dipping or virtually any other method. The resulting coatings exhibited no cytotoxicity in in vitro tests according to DIN 10933-5. "Blood compatibility studies were also successful. The coatings caused minimal activation of the coagulation cascade and platelets," reports Köcher.

Find more information at www.bayermaterialscience.com.